Answer:
x = 1 ±√89
Step-by-step explanation:
We have the equation:
(x+7)(x-9) = 25
Using distributive property:
x(x-9) + 7(x-9) = 25
x²- 9x + 7x - 63 -25 = 0
x²- 2x - 88 = 0
To complete squares we need to add and subtract 1, as follows:
x²- 2x - 88 +1 -1 = 0
x²- 2x +1 -88 -1 = 0 (this is a perfect square)
(x - 1)² - 89 = 0
Solving for x:
(x - 1)² = 89
x - 1 = ±√89
x = 1 ±√89
Answer:
h - 18 = 67
Step-by-step explanation:
If h is her height, then her height minus 18 is 67, or h - 18 = 67
Answer:
520 m
Step-by-step explanation:
Perimeter is the distance around a shape. To find the perimeter, you add up all the sides.
200 + 60 + 60 + 200 = 520 m
Answer:
see below
Step-by-step explanation:
f(x) = 2x + 9,
Let x = -1
f(-1) = 2(-1) +9
= -2 +9
= 7
Answer:
₹900
Step-by-step explanation:
Let x represent the amount loaned at 10%. Then (1500-x) is the amount loaned at 7%, and the total interest for 3 years is ...
i = Prt
396 = x(0.10)(3) + (1500-x)(0.07)(3)
396 = 0.09x +315 . . . . . simplify
81 = 0.09x . . . . . . . . . . . subtract 315
81/0.09 = x = 900 . . . . . divide by the coefficient of x
The sum lent at 10% was ₹900.
