Answer:

Step-by-step explanation:
Let the number be x.
Translating the word problem into an algebraic equation, we have;
Opening the bracket, we have;

Collecting like terms, we have;

Four oranges cost 90 cents, an orange costs 90/4 cents, which is around 22.5 cents. Multiply this by 36 to get the cost of 3 dozen oranges, so 22.5 times 36 is 810, 810 cents, or 8.10 dollars.
Step-by-step explanation:

The product of
is negative whereas the product of 
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.

C because eof plus fob will end up being 180