a) 15 + x - 5 = 20
15 + x = 20 + 5
15 + x = 25
x = 25 - 5
x = 20
b) y x 5 = 10 x 2
y x 5 = 20
y = 20 : 5
y = 4
a. x=20+5-15
x=10
b.y x 5=20
y=20/5
y=4
k nhes
a) 15 + x - 5 = 20
x = 20 + 5 - 15
x = 10
b) y x 5 = 10 x 2
y x 5 = 20
y = 20 : 5
y= 4
OK
a) 15 + x - 5 = 20
15 + x = 20 + 5
15 + x = 25
x = 25 - 15
x = 10
b) y x 5 = 10 x 2
y x 5 = 20
y = 20 : 5
y = 4
a, 15 + x = 20 + 5 = 25
x = 25 - 15
x = 10
b, y x 5 = 20
y = 20 : 5 = 4
=> y = 4
a ) 15+x- 5 = 20
x = 20+5
x = 25 - 15
x = 15
b) y x 5 = 10x2
x = 20
x = 20: 5
x = 4
k tớ đi , làm ơn !
15+x-5=20
=>x-5=20-15
=>x-5=5
=>x =5+5
=>x = 10
yx5=10x2
=>yx5=20
=>y = 20:5
=>y =4