Câu hỏi của Hà Trần

Question

Tìm X

a) (X x 7 + 8) : 5 = 10

b) (X + 5) x 19 : 13 = 57

c) 4 x (36 – 4 x X) = 64

d) 7,6 : 1,9  x X = 3,2

e) (X : 2 + 50) : 5 = 12

g) 280 : (7 + 3 x X) = 4...

Nguyễn Thanh Hằng · Accepted Answer

a) $\left(x.7+8\right):5=10$

$x.7+8=10.5$

$x.7+8=50$

$x.7=50-8$

$x.7=42$

$x=42:7$

$x=6\left(tm\right)$

Vậy ......................

b) $\left(x+5\right).19:13=57$

$\left(x+5\right).19=57.13$

$\left(x+5\right).19=741$

$x+5=741:19$

$x+5=39$

$x=39-5$

$x=34\left(tm\right)$

Vậy ..................

c) $4\left(36-4x\right)=64$

$36-4x=64:4$

$36-4x=18$

$4x=36-18$

$4x=18$

$x=\dfrac{18}{4}$

Vậy ....................

d) $7,6:1,9.x=3,2$

$4x=32$

$x=32:4$

$x=8\left(tm\right)$

Vậy ................Câu trả lời: a) $\left(x.7+8\right):5=10$