Answer:
=1
Step-by-step explanation:
(-2-√3)(-2+√3)
=-2(-2+√3)-√3(-2+√3)
=4-2√3+2√3-√9
=4-3
=1
Answer:
x=8a
Step-by-step explanation:
3/a x-4=20
We need to solve for x
Add 4 to each side
3/a x-4+4=20+4
3/a x = 24
Multiply each side by a/3 so we can get x alone
a/3 *3/a x = 24 * a/3
x = 8a
Let 'x' represent the amount of 50% mixture used, then '20-x' represents the amount of 10% mixture used
0.25(20) = 0.50x + 0.10(20-x)
solving for 'x' we have x=7.5
20-7.5 = 12.5
7.5 pounds of 50% mixture should be combined with 12.5 pounds of 10% mixture
