The answer is x²+10x+21
(x+3)(x+7)
=(x+3)(x+7)
=(x)(x)+(x)(7)+(3)(x)+(3)(7)
=x²+7x+3x+21
=x²+10x+21
Answer:
[tex] {x }^{2} + 10x + 21[/tex]
Step-by-step explanation:
[tex](x + 3)(x + 7) \\ = x \times x + 3 \times x + 7 \times x + 3 \times 7 \\ = {x}^{2} + (3 + 7) x + 21 \\ = {x}^{2} + 10x + 21[/tex]
