I think this may be multiplication so 5 times 10 equls50
77/5=99/x
77x=5*99
77x=495
x=495/77
x=6.4
she needs to study 6.4 hrs to get 99
500 = 10x + 2 * 15 * 5 + 15x
500 = 25x + 150
500 - 150 = 25x
350 = 25x
x = 14
Triangular ends: 14 * 10 = 140
Base rectangle: 14 * 15 = 210
side rectangles: 5 * 15 * 2 = 150
140 + 210 + 150 =
Answer: 5x(x+3)
Step-by-step explanation: hope this helps
Answer:D
Step-by-step explanation: