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//