Question

(5x-7)(x+3) = 5x² +5x

Answer 1

$(5x - 7)(x + 3) = {5x}^{2} + 5x \\ {5x}^{2} + 15x - 7x - 21 = {5x}^{2} + 5x \\ 15x - 7x - 21 = 5x \\ - 21 = - 3x \\ x = 7$

Answer 2

The expression (5x - 7)(x + 3) can be simplified using the distributive property, also known as FOIL (First, Outer, Inner, Last). Here's how you can do it step by step:

(5x - 7)(x + 3)

First, multiply the first terms in each parentheses: (5x)(x) = 5x^2

Next, multiply the outer terms: (5x)(3) = 15x

Then, multiply the inner terms: (-7)(x) = -7x

Finally, multiply the last terms: (-7)(3) = -21

Now, combine all these results: 5x^2 + 15x - 7x - 21

Combine like terms: 5x^2 + 8x - 21

So, (5x - 7)(x + 3) simplifies to 5x^2 + 8x - 21.