Question

a). afla nr a , dacă ab+ac=520 si b+c=52
b). afla nr a , dacă ab-ac=45 si b-c=9
c). afla suma b+c dacă ab+ac+70=170 si a=25
d). afla diferența b-c , dacă ab-ac-48=2 si a= 10

Va rog repede!

Answer 1

a) ab+ac=520
a(b+c)=520
a×52=520
a=520:52
a=10

b)ab-ac=45
a(b-c)=45
a×9=45
a=45:9
a=5

c)ab+ac+70=170
ab-ac=170-70
ab-ac=100
a(b+c)=100
25(b+c)=100
b+c=100:25
b+c=4

d)ab-ac-48=2
ab-ac=2+48
ab-ac=50
a(b-c)=50
10(b-c)=50
b-c=50:10
b-c=5