Answer:
the first one and the last one
Step-by-step explanation:
trust me

If two fractions have the same numerator, the fraction with the smaller denominator is bigger.

3/8 is bigger.
Answer:
(5x + 7y)² = 25x² + 70xy + 49y²
Step-by-step explanation:
(5x + 7y)² = 25x² + 70xy + 49y²
Because,
(5x + b)² = (5x)² + 2(5x)(b) + b²
2(5x)(b) = 70xy
b = 7y
b² = (7y)² = 49y²