Answer:
A
Step-by-step explanation:
the standard form of a quadratic equation is
ax² + bx + c = 0 : a ≠ 0
obtain (5 + x)(5 - x) = 7 in this form by expanding the factors
25 - x ² = 7 ( subtract 7 from both sides )
18 - x² = 0 ( multiply through by - 1 )
x² - 18 = 0 ← in standard form
with a = 1, b= 0 and c = - 18 → A
Answer: x = 23 and y = 13
Explanation:
let x and y be the two number.
Where:
(x + y)/2 = 18 => x + y = 18 x 2 = 36
and:
x - y = 10
Thus we get:
x + y = 36 (1)
x - y = 10 (2)
Add (1) and (2):
x + y + x - y = 36 + 10
2x = 46
x = 23
If x = 23
then x - y = 10
23 - y = 10
-y = -13
y = 13
Answer: 4x² + x - 2
Step-by-step explanation: First distribute the -2x into (1-3x) which = -2x + 6x²
Now let's work on the second part:
Distributing (2x + 3) to (3x - 2) = 6x² - 4x + 9x - 6. Combining like terms: 6x² - 4x + 9x - 6 --> 6x² + 5x - 6. Now let's combine the like factors of our two equations which equals
12x² + 3x - 6. Now reduce by dividing by 3 which gives us the final answer of:
4x² + x - 2.
The anwser is a !!!!!!!!!!!
