Answer:
x = 12
Step-by-step explanation:
5x + 15 = 75
-15 -15
5x = 60
x = 12
Answer:

Step-by-step explanation:
x² = 19x + 12
⇔ x² - 19x - 12 = 0
Calculating the discriminant :
b² - 4ac = (-19)² - 4×1×(-12) = 409
The discriminant is positive ,then the equation has two solutions.

8/9 divided by 10/3= 4/15