Answer:
12.68 de
Step-by-step explanation:
Step 1: multiply the numbers in front of the parentheses with each term inside the parentheses
15p - 9 = 5p - 5
Step 2: get like terms on the same side
10p = 4
Step 3: divide both sides by 10
p = 4/10
Step 4: simplify
p = 2/5
18a is correct, 18b is incorrect, 18c is correct, 18d is false, 18e is false, 18f is true, 19 is incorrect.
Answer:
see explanation
Step-by-step explanation:
(43)
3
- 75x³ ← factor out 3x³ from each term
= 3x³(x² - 25) ← this is a difference of squares and factors in general as
a² - b² = (a - b)(a + b) , thus
x² - 25 = x² - 5² = (x - 5)(x + 5)
Thus
3
- 75x³ = 3x³(x - 5)(x + 5)
(44)
81c² + 72c + 16 ← is a perfect square of the form
(ac + b)² = a²c² + 2abc + b²
Compare coefficients of like terms
a² = 81 ⇒ a =
= 9
b² = 16 ⇒ b =
= 4
and 2ab = 2 × 9 × 4 = 72
Thus
81c² + 72c + 16 = (9c + 4)²
Answer:
n = 9
Step-by-step explanation:
7n + 5 = 68
7n + 5 - 5 = 68 - 5
7n = 63
7n / 7 = 63 / 7
n = 9