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
Speed = distance/time
So speed = 40/10
= 4m/s
Answer: The answer is (4, 600)
Step-by-step explanation:
Answer:
x = 20
Step-by-step explanation:
the sum of the interior angles of a triangle is 180°
add expressions for each angle then combine 'like terms':
6x - 5 + 2x - 3 + x + 8 = 180
9x - 8 + 8 = 180
9x = 180
x = 180/9
x = 20
The Solution.
The correct answer is a rotation and then a dilation. (option C)
