Question

afla numarul necunoscut:8×10-a=9×7;10×2+b=6×(2×5);c-10×7=5×6;d+3×10=7×7;

Answer 1

8×10-a=9×7
80-a=63
a=80-63
a=17

10×2+b=6×(2×5)
20+b=6×10
20+b=60
b=60-20
b=40

c-10×7=5×6
c-70=30
c=30+70
c=100

d+3×10=7×7
d+30=49
d=49-30
d=19

Answer 2

80-a=63 ;a=80-63=17  ;20+b=60;b=60-20=40  ;c-70=30;c=100   ;d+30=49;d=19