diff --git a/Lab2_1/1a.asm b/Lab2_1/1a.asm
new file mode 100644
index 0000000..9d775de
--- /dev/null
+++ b/Lab2_1/1a.asm
@@ -0,0 +1,51 @@
+#Data segment
+	.data
+So1:	.word	0
+So2:	.word	0
+So3:	.word	0
+Ketqua:	.word	0
+#Cac cau nhac nhap du lieu
+Nhap1:	.asciiz	"Nhap so thu 1: "
+Nhap2:	.asciiz "Nhap so thu 2: "
+Nhap3:	.asciiz	"Nhap so thu 3: "
+Xuat:	.asciiz "Tong cua 3 so la: "
+#Code segment
+	.text
+	.globl	main
+main:
+#Nhap 3 so
+	la	$a0, Nhap1	#Nhap so thu 1
+	li	$v0, 4
+	syscall
+	li	$v0, 5
+	syscall
+	sw	$v0, So1
+	la	$a0, Nhap2	#Nhap so thu 2
+	li	$v0, 4
+	syscall
+	li	$v0, 5
+	syscall
+	sw	$v0, So2
+	la	$a0, Nhap3	#Nhap so thu 3
+	li	$v0, 4
+	syscall
+	li	$v0, 5
+	syscall
+	sw	$v0, So3
+#Xu ly
+	lw	$t0, So1
+	lw	$t1, So2
+	add	$t0, $t0, $t1
+	lw	$t1, So3
+	add	$t0, $t0, $t1
+	sw	$a0, Ketqua
+#Xuat ket qua
+	la	$a0, Xuat
+	li	$v0, 4
+	syscall
+	la	$a0, 0($t0)
+	li	$v0, 1
+	syscall
+#exit
+	li	$v0, 10
+	syscall
diff --git a/Lab2_1/1b.asm b/Lab2_1/1b.asm
new file mode 100644
index 0000000..14a27bc
--- /dev/null
+++ b/Lab2_1/1b.asm
@@ -0,0 +1,10 @@
+	.data
+Chuoi:	.asciiz	"Kien truc may tinh 2017"
+	.text
+	.globl	main
+main:
+	la	$a0, Chuoi
+	li	$v0, 4
+	syscall
+	li	$v0, 10
+	syscall
diff --git a/Lab2_1/1c.asm b/Lab2_1/1c.asm
new file mode 100644
index 0000000..95f7392
--- /dev/null
+++ b/Lab2_1/1c.asm
@@ -0,0 +1,22 @@
+	.data
+Chuoi:	.space	11
+Nhap:	.asciiz	"Nhap chuoi can xuat:\n"
+Xuat:	.asciiz	"\nXuat chuoi:\n"
+	.text
+	.globl	main
+main:
+	la	$a0, Nhap
+	li	$v0, 4
+	syscall
+	la	$a0, Chuoi
+	li	$a1, 11
+	li	$v0, 8
+	syscall
+	la	$a0, Xuat
+	li	$v0, 4
+	syscall
+	la	$a0, Chuoi
+	li	$v0, 4
+	syscall
+	li	$v0, 10
+	syscall
\ No newline at end of file
diff --git a/Lab2_1/2a.asm b/Lab2_1/2a.asm
new file mode 100644
index 0000000..4d6a136
--- /dev/null
+++ b/Lab2_1/2a.asm
@@ -0,0 +1,21 @@
+	.data
+Const:	.word	66000
+	.text
+	.globl	main
+main:
+	lw	$t0, Const
+	addi	$t0, $t0, 30
+	addi	$t0, $t0, 30
+	addi	$t0, $t0, 30
+	addi	$t0, $t0, 30
+	addi	$t0, $t0, 30
+	addi	$t0, $t0, 30
+	addi	$t0, $t0, 30
+	addi	$t0, $t0, 30
+	addi	$t0, $t0, 30
+	addi	$t0, $t0, 30
+	addi	$t0, $t0, -6000
+	addi	$t0, $t0, 25
+	ori	$s0, $t0, 0
+	li	$v0, 10
+	syscall
diff --git a/Lab2_1/2b.asm b/Lab2_1/2b.asm
new file mode 100644
index 0000000..730fc27
--- /dev/null
+++ b/Lab2_1/2b.asm
@@ -0,0 +1,16 @@
+	.data
+Const:	.word	66000
+	.text
+	.globl	main
+main:
+	lw	$t0, Const
+	li	$t1, 30
+	sll	$t2, $t1, 3
+	sll	$t1, $t1, 1
+	add	$t1, $t1, $t2
+	add	$t0, $t0, $t1
+	addi	$t0, $t0, -6000
+	addi	$t0, $t0, 25
+	ori	$s0, $t0, 0
+	li	$v0, 10
+	syscall
diff --git a/Lab2_1/3.asm b/Lab2_1/3.asm
new file mode 100644
index 0000000..fa57a44
--- /dev/null
+++ b/Lab2_1/3.asm
@@ -0,0 +1,88 @@
+	.data
+a:	.word	0
+b:	.word	0
+c:	.word	0
+d:	.word	0
+x:	.word	0
+kq:	.word	0
+nhap_a:	.asciiz	"Nhap a: "
+nhap_b:	.asciiz	"Nhap b: "
+nhap_c:	.asciiz	"Nhap c: "
+nhap_d:	.asciiz	"Nhap d: "
+nhap_x:	.asciiz	"Nhap x: "
+xuat:	.asciiz	"Ket qua cua bieu thuc la: "
+	.text
+	.globl	main
+main:
+	#Nhap a
+	la	$a0, nhap_a
+	li	$v0, 4
+	syscall
+	li	$v0, 5
+	syscall
+	sw	$v0, a
+	#Nhap b
+	la	$a0, nhap_b
+	li	$v0, 4
+	syscall
+	li	$v0, 5
+	syscall
+	sw	$v0, b
+	#Nhap c
+	la	$a0, nhap_c
+	li	$v0, 4
+	syscall
+	li	$v0, 5
+	syscall
+	sw	$v0, c
+	#Nhap d
+	la	$a0, nhap_d
+	li	$v0, 4
+	syscall
+	li	$v0, 5
+	syscall
+	sw	$v0, d
+	#Nhap x
+	la	$a0, nhap_x
+	li	$v0, 4
+	syscall
+	li	$v0, 5
+	syscall
+	sw	$v0, x
+	#Xu ly
+	lw	$a0, x
+	lw	$a1, a
+	jal	times
+	ori	$s0, $v0, 0
+	lw	$a1, b
+	sub	$s0, $s0, $a1
+	ori	$a1, $s0, 0
+	jal	times
+	ori	$s0, $v0, 0
+	lw	$a1, c
+	sub	$s0, $s0, $a1
+	ori	$a1, $s0, 0
+	jal	times
+	ori	$s0, $v0, 0
+	lw	$a1, d
+	add	$s0, $s0, $a1
+	sw	$s0, kq
+	j	exit
+times:
+	ori	$t0, $a0, 0
+	li	$t1, 0
+loop:	beq	$t0, 0, return
+	add	$t1, $t1, $a1
+	addi	$t0, $t0, -1
+	j	loop
+return:	ori	$v0, $t1, 0
+	jr	$ra
+exit:
+	la	$a0, xuat
+	li	$v0, 4
+	syscall
+	lw	$a0, kq
+	li	$v0, 1
+	syscall
+	li	$v0, 10
+	syscall
\ No newline at end of file
diff --git a/Lab2_1/4a.asm b/Lab2_1/4a.asm
new file mode 100644
index 0000000..3c11e62
--- /dev/null
+++ b/Lab2_1/4a.asm
@@ -0,0 +1,18 @@
+	.data
+array:	.word	0, 1, 2, 3, 4, 5, 6, 7, 8, 9
+kq:	.asciiz	"Ket qua la: "
+	.text
+	.globl	main
+main:
+	la	$a0, array
+	lw	$t0, 12($a0)
+	lw	$t1, 24($a0)
+	addu	$t0, $t0, $t1
+	la	$a0, kq
+	li	$v0, 4
+	syscall
+	move	$a0, $t0
+	li	$v0, 1
+	syscall
+	li	$v0, 10
+	syscall	
diff --git a/Lab2_1/4b.asm b/Lab2_1/4b.asm
new file mode 100644
index 0000000..d029b2b
--- /dev/null
+++ b/Lab2_1/4b.asm
@@ -0,0 +1,43 @@
+	.data
+string:	.space	32
+in:	.asciiz	"Nhap chuoi can bien doi: "
+wrong:	.asciiz	"Chuoi da nhap khong hop le!"
+out:	.asciiz	"Chuoi sau khi bien doi la: "
+	.text
+	.globl	main
+main:
+	la	$a0, in
+	li	$v0, 4
+	syscall
+	la	$a0, string
+	li	$a1, 32
+	li	$v0, 8
+	syscall
+	move	$t1, $a0
+loop:
+	lb	$t2, 0($t1)
+	addi	$t1, $t1, 1
+	bnez	$t2, loop
+exe:
+	addi	$t1, $t1, -3
+	ble	$t1, $a0, error
+	lb	$t4, 0($a0)
+	lb	$t5, 0($t1)
+	sb	$t4, 0($t1)
+	sb	$t5, 0($a0)
+	j	write
+error:
+	la	$a0, wrong
+	li	$v0, 4
+	syscall
+	j	exit
+write:
+	la	$a0, out
+	li	$v0, 4
+	syscall
+	la	$a0, string
+	li	$v0, 4
+	syscall
+exit:
+	li	$v0, 10
+	syscall