Good morning or good afternoon i want to know the answer of this equation 156×4 and estimate and record the product like this

In which form is the following function written? y = - 2(x – 3)(x + 5)

Astudent must have an average on five test that is greater than it equal to 80% but less than 90% to receive a final grade of b. devon's greades on the first four test were 78% 62% 91% and 80% what range if grades on the fifth test would give him a b in the course? ( assuming the highest grade is 100%)

Would greatly appreciate these 3 answers