x^2 + 6xy + 8y2
4x^2 + 3xy + 2y^2 - 5x^2 + 2xy + 6y^2
= 4x^2 + 3xy + 2y^2 + -5x^2 + 3xy + 6y^2
Combine like terms:
= 4x^2 + 3xy + 2y^2 + -5x^2 + 3xy + 6y^2
= (4x^2 + -5x^2) + (3xy + 3xy) + (2y^2 + 6y^2)
= -x^2 + 6xy + 8y^2
I was confused at first until I realized that you'd shared not one, not two, but three questions in one post. would you please post just one question at a time to avoid this.
I'll focus on your second question only: Solve <span>3 + |2x - 4| = 15.
Subtr. 3 from both sides. Result: |2x - 4| = 12
Divide all terms by 2, to reduce: |x - 2| = 6
Case 1: x-2 is already +, so we don't need | |:
x - 2 = 6 => x = 8 (first answer)
Case 2: x-2 is negative, so |2x-4| = -(2x-4) = 6
Then -2x + 8 = 6. Subtr. 8 from both sides: -2x = -2
Div both sides by -2: x = 1 (second answer)
Be sure to check these results by subst. them into the original equation.
Please post your other questions separately. Thanks and good luck!
</span>
Answer:
B. 54
Explanation:
Take 72 from 180.
180 - 72 = 108.
Since there are two y's AND they're congruent, divide 108 by two and get 54.
Answer:
y=6
Step-by-step explanation:
use elimination by making the ys opposite in value and eliminating them from the equation so there is only variable:
-3x+2y=6
2(4x-y=2)
-3x+2y=6
8x-2y=4
Combine like terms and divide by 5 on both sides.
5x=10
x=2
Plug x in to find y:
4(2)-y=2
8-y=2
y=6
Answer:
A. I can't quite see the question, but I'm pretty sure it's A
Step-by-step explanation:
Sin(A) = 1/3
Sin^2(A) + Cos^2(A) = 1
(1/3)^2 + cos^2(A) = 1
1/9 + cos^2(A) = 1
cos^2(A) = 1 - 1/9
cos^2(A) = 8/9
cos(A) = √(8/9)
√8 = √(2 * 2 * 2) = 2√2
√9 = 3
cos(A) = 2√2/3
