Question

1. Rezolvati ecuatiile :
a)2x+90=4x
b)3.5x=120-2.5x

2. Aflati doua numere naturale , stiind ca impartind pe unul la celalalt obtinem catul 10 si restul 3 , iar suma lor este 69 .

Answer 1

2x + 90 = 4x
90 = 4x - 2x
90 = 2x
x = 90 ; 2
x = 45

3 , 5 x = 120 - 2, 5 x
3 , 5 x + 2 , 5 x = 120
6x = 120
x = 120 : 6
x = 20

a + b = 69
a ; b = 10 rest 3
a = 10 b + 3
10 b + 3 + b = 69
11b = 69 - 3
11b = 66
b = 66 : 11
b = 6

Answer 2

a) 2x+90=4x
2x-4x=-90
-2x=-90       inmultim -1
2x=90
x=90/2
x=45

b) 3,5x=120-2,5x
3,5x+2,5x=120
6x=120
x=120/6
x=20

2) a:b=10 rest 3
a=10b+3
a+b=69
10b+3+b=69
11b=69-3
11b=66
b=66/11
b=6
a=10b+3=10·6+3=60+3
a=63

verificare 63:6=10 rest 3