Multiply. (5x + 7)2 A. 25x2 + 35x + 49
B. 25x2 – 70x + 49
C. 25x2 + 70x + thing
D. 25x2 + 49

(5x + 7)² = 25x² + 70x + 49 ⇒ C

Step-by-step explanation:

The steps of solving the square binomial: (ax + b)²

1. (ax + b)² = (ax + b)(ax + b)

2. (ax + b)(ax + b) = (ax × ax) + (ax × b) + (b × ax) + (b × b) = a²x² + abx + abx + b²

3. Add the like terms ⇒ a²x² + (abx + abx) + b² = a²x² + 2abx + b²

Then (ax + b)² = a²x² + 2abx + b²

Let us use the same steps to solve the question

∵ (5x + 7)² = (5x + 7)(5x + 7)

∴ (5x + 7)(5x + 7) = (5x)(5x) + (5x)(7) + (7)(5x) + (7)(7)

∴ (5x + 7)(5x + 7) = 25x² + 35x + 35x + 49

→ Add the like terms

∵ 25x² + 35x + 35x + 49 = 25x² + (35x + 35x) + 49 = 25x² + 70x + 49

∴ (5x + 7)(5x + 7) = 25x² + 70x + 49

→ Then equate (5x + 7)² by the right side above

∴ (5x + 7)² = 25x² + 70x + 49

correct answer is c. just did it

step-by-step explanation: