-2 is the answer because you do the change of y over the change of x.
Answer:
see explanation
see explanationStep-by-step explanation:
21
Note that
(a - 
)²
= a² - 2 + 
= a² + - 2
= 11 - 2
= 9
Thus
(a - )² = 9 ( take the square root of both sides )
a - = 3
22
Since the expression is a perfect square, then
(4x + 5y)²
= 16x² + 40xy + 25y²
Comparing coefficients, then
a - 1 = 40 ( add 1 to both sides )
a = 41
23
99² - 87² ← is a difference of squares and factors as
= (99 - 87)(99 + 87)
= 12 × 186 = 1152, thus
24a = 1152 ( divide both sides by 24 )
a = 48
Answer:
160
Step-by-step explanation:
15% + 5% = 20%
80%=0.8
200x0.8=160
Answer:
a) y = 16/x²
b) x = 4/5
Step-by-step explanation:
You want the equation for y in terms of x when y is inversely proportional to the square of x, and y is 16 when x is 1. Further, you want the value of x when y is 25.
<h3>(a) Relation</h3>
The wording "inversely proportional to the square" means the form of the equation is ...
y = k/x² . . . . . . where k is the constant of proportionality
The value of k can be found from the given (x, y) pair.
k = x²y = (1)²(16) = 16
The equation is ...
y = 16/x²
<h3>(b) Value of x</h3>
Solving for x gives ...
x = √(16/y)
Then the value of x for y = 25 is ...
x = √(16/25)
x = 4/5
