Answer:
Step-by-step explanation:
12a)To rationalize the denominator, multiply the denominator and numerator by √5.

b) (a+b)² = a² + 2ab + b²
(1 +√3)² = 1² + 2*1*√3 + (√3)²
= 1 + 2√3 + 3
= 4 + 2√3
a = 4 ; b =2
13) (a + b)(a - b) = a² - b²

Answer:
(b)
Step-by-step explanation:
A suitable calculator or spreadsheet can find the matrix product for you. Here, the answer choices differ in their upper left term, so we can determine the correct choice by finding the value of that term. It is the dot product of the first row of B and the first column of A.
(5)(3) +(7)(3) +(3)(2) = 15 +21 +6 = 42
This matches choice B.
Answer:
Step-by-step explanation:
r²+8r=−7
Step 1: Subtract -7 from both sides.
r²+8r−(−7)=−7−(−7)
r²+8r+7=0
Step 2: Use quadratic formula with a=1, b=8, c=7.
r=

Consider a right triangle in which one of the angles
satisfies

That is, the side opposite
occurs in a ratio of 3 to 5 with the hypotenuse. The side adjacent to
then occurs in a ratio of 4 to 5 with the hypotenuse. In other words,

because

Then in this triangle,
