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:
x = 3
Step-by-step explanation:
First, multiply all four terms by 10 to eliminate the fractions:
4x - 8(x-4) = 13x - 19
Next, carry out the indicated multiplication, obtaining:
4x - 8x + 32 = 13x - 19
Combining the x terms, we get:
-4x + 32 = 13x - 19, or
32 = 17x - 19
Combining the constants, we get 51 = 17x, and so x = 51/17 = 3.
Answer:
D.
Step-by-step explanation:
Answer:
6,-3
Step-by-step explanation:
Answer:
24.25 feet
Step-by-step explanation: