Please help me please

Answer:
3) [tex]x^{2}[/tex] + 4x - 21
Step-by-step explanation:
(x - 3)(x + 7)
Distribute:
x(x + 7)
-3(x + 7)
x(x) = [tex]x^{2}[/tex]
x(7) = 7x
-3(x) = -3x
-3(7) = -21
Combine like terms:
7x - 3x = 4x
Put it together:
[tex]x^{2}[/tex] + 4x - 21
Answer: x²+ 4x - 21
Let's do this step-by-step.
1. Apply the foil method. (formula: (a + b)(c + d) = ac + ad + bc + bd)
F - First
O - Outer
I - Inner
L - Last
= xx + x × 7 + (-3)x + (-3) × 7
2. Apply the minus and plus rules. + (-a) = -a
xx + 7x - 3x - 3 × 7
3. Simplify.
Hence, the answer is x² + 4x - 21
Let me know if you have any questions.
~ Lily, from Brainly.