Can you help me with these questions

see below (I hope this helps!)

Step-by-step explanation:

41. √20 = √4 * 5 = √4 * √5 = 2√5

43. The sum of interior angles in a triangle is 180°, therefore, x = 180 - (75 + 64) = 41°.

45. 15 + 5(2x - 3) = 15 + 5(2x) + 5(-3) = 15 + 10x - 15 = 10x

47. Complementary angles have a sum of 90°, therefore, x = 90 - 48 = 42°.

let's call the solutions x₁ = (5 - 2√7)/3 and x₂ = (5 + 2√7)/3

then the equation is (x-x₁)(x-x₂) = 0

if you fill that in you get a lot of numbers which you can recognize as ax²+bx+c=0.

step-by-step explanation:

you can see that a=1 (there is just an x²)

b = (-5 -2√7 + 2√7 - 5)/3 = -10/3

c = -2√7)/3 ) * (-5+2√7)/3) = -1/3

so your answer is 3x^2 – 10x – 1 = 0