Respuesta :

Answer:

11.25

77.85

Step-by-step explanation:

1.6x + 3 = 21

use inverse operation (+ = -, x = ÷) by taking 3 to the opposite side and changing it's integer to negative

1.6x = 21 - 3

divide 2 sides by 1.6

1.6x = 18

1.6x/1.6 = 18/1.6

x = 11.25//

2.15(x-5)=75

inverse operation

x= 75 - 2.15 + 5

x= 77.85//