Question

Expand :
1. (5x + 4y)^2
2. (x + 3)^2
3. (2a + 7)^2​

Answer 1

Answer:

double the numbers

Step-by-step explanation:

1. 25x^2+16y^2

2. x^2+9

3.4a^2+14

I hope this answer is right and it helps u

Answer 2

Answer:

$1- {(5x + 4y)}^{2} \\ = {(5x)}^{2} + {(4y)}^{2} + 2 \times 5x \times 4y \\ = 25 {x}^{2} + 16 {y}^{2} + 40xy \\ \\ 2 - \: {( x + 3)}^{2} \\ = {(x)}^{2} + {(3)}^{2} + 2 \times x \times 3 \\ = {x}^{2} + 9 + 6x \\ \\ 3 - \: {(2a + 7)}^{2} \\ = {(2a)}^{2} + {(7)}^{2} + 2 \times 2a \times 7 \\ = 4 {a}^{2} + 49 + 28a$