x² - 80 = 0
Add 80
to each side: x² = 80
Square root
each side: x = √80
Look it up: x = + 8.944... (rounded)
and
x = - 8.944... (rounded).
___________________________________
Here's a cleaner solution:
x² - 80 = 0
Add 80
to each side: x² = 80
Square root
each side: x = √80
But 80 = 16 · 5
So √80 = √16 · √5
√16 = 4, so x = 4 √5
Answer:
substract 4 from both sides..?
Step-by-step explanation:
Answer:Associative Properties
Step-by-step explanation:
Answer:
6 and 3
Step-by-step explanation:
let x and y be the 2 numbers with x > y , then
2x + 3y = 21 → (1)
x - y = 3 → (2)
Multiplying (2) by 3 and adding the result to (1) will eliminate y
3x - 3y = 9 → (3)
Add (1) and (3) term by term to eliminate y
5x = 30 ( divide both sides by 5 )
x = 6
Substitute x = 6 into either of the 2 equations and solve for y
Substituting into (1)
2(6) + 3y = 21
12 + 3y = 21 ( subtract 12 from both sides )
3y = 9 ( divide both sides by 3 )
y = 3
The 2 numbers are 6 and 3
