The answer is 12 and 4 because 4 times 2 is 8 and if you add that by four more that would equal 12 the same amount as the first nubmer
Answer:
-17
Step-by-step explanation:
f(-x)-11x-28
-11(-1)-28
11-28
-17
Answer:
0.00888888889 is the correct answer
Answer:
x^2 + 5x - 84 = 0
x = 7
Step-by-step explanation:
let the sister's age = y
sister's age (y) = 5 + x equation 1
xy = 84 equation 2
Make y the subject of the formula in equation 2
y = 84/x
equate equation 1 and 2
84/x = 5 + x equation 3
Multiply equation 3 by x
84 = 5x + x^2
x^2 + 5x - 84 = 0
tjis can be solved using quadratic equation
x^2 -7x + 12x -84 = 0
x(x + 12) -7(x + 12)
x = 7 or - 12
age cant be negative so his age is 7
