All you need to know is that

So, the first function grows exponentially and the second decays exponentially. The rate of growth/decay are the bases of the exponentials, which means 1.08 and 0.205
Answer: -4
Step-by-step explanation: I am guessing you meant ...99 + 2(8*3)...
3x + 99 + 2(8 x 3) = 135
3x + 99 + 2(24) = 135
3x + 99 +48 = 135
3x + 147 = 135
(3x + 147) - 147 = (135) - 147
3x = -12
(3x) ÷ 3 = (-12) ÷ 3
x = -4
Step-by-step explanation:
Let grandson's age be x.
Let grandpa's age be y {equation : y = 8+5x}
so,
x + y = 88
or, x + 8+ 5x = 88 (substituting the value of y)
or, 6x + 8 =88
or, 6x = 88-8
or, 6x = 80
or, x = 80/6
so, x = 13.33
so grandson's age = 13.33
grandpa's age = 8 + 5x = 8 + (5×13.33) = 74.65 yrs
Any angle that measures less than 90 degree is known as "Acute angle"
In short, Your Answer would be: "Acute Angle"
Hope this helps!