Answer:
Step-by-step explanation:
a² - b² = (a + b)(a - b)
48² + x² = 50²
x² = 50² - 48²
= (50 +48)(50 -48)
= 98 * 2
x² = 196
x = √196

Can I see the number line?
7(3 + 9) = 7(3) + 7(9) = 21 + 63
I should know this but I guess I don't, try going on x-actoschoolpro.com ;)