Answer:
a = - 5, a = - 3
Step-by-step explanation:
Given
a² + 8a + 15 = 0 ← in standard form
(a + 3)(a + 5) = 0 ← in factored form
Equate each factor to zero and solve for a
a + 3 = 0 ⇒ a = - 3
a + 5 = 0 ⇒ a = - 5
Answer:
E
because both sides are equal when substituted by 3 & 5
Answer:
x = 7
Step-by-step explanation:
To solve:
Distribute 5 among everything inside the first parentheses. You'll get 5x - 15.
Next distribute -2 among everything in the second parentheses. You'll get
-2x - 2.
<u>All together: 5x - </u><u>15</u><u> </u><u>-</u><u>2x </u><u>-</u><u> </u><u>2</u><u> </u><u>= 4</u>
Now combine like terms:
5x - 2x = 3x and -15 - 2 = - 17
<u>All</u><u> </u><u>together</u><u>: 3x -</u><u> </u><u>17 = 4</u>
Add 17 on both sides to get 21, and then divide both sides by 3. Answer is x = 7.
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Last, don't forget to check your work.
You can plug in 7 for x to get:
5(7 - 3) = 20
5 × 7 = 35
5 × -3 = -15
35 - 15 = 20
-2(7 + 1) = -16
-2 × 7 = -14
-2 × 1 = - 2
-14 -2 = -16
<u>20 - 16 = 4</u>
⬆⬆⬆Therefore this is correct.
Sorry this is a bit lengthy, but hope this helps :)
