The other person did not explain so I will:
(68+79+74)= 221/3 =73.7
80 x 4 = 320
320-221 = 99
He must get 99 on his 4th test.
Thanks
Answer:
b is the answer
Step-by-step explanation:
Answer:
4x^2 + 9x + 4 = 0
Using the quadratic formula:
x = [-9 +- sqrt(81 - (-64)] / 2 * 4
x = [-9 +- sqrt (145)] / 8
So, the solution is your second answer:
negative 9 plus or minus the square root of 145 divided by 8.