Answer:
-$7
Step-by-step explanation:
20 - 15 = 5
5 + 5 = 10
10 - 10 = 0
0 - 7 = -7
Answer:2
Step-by-step explanation;
Answer:
8 boards.
Step-by-step explanation:
Since he bought a few of each length. The only combination that works is when he bought 5 of the 4 ft long board so 4×5=20. Than he bought 3 of the 5ft boards 3×5=15. 20+15=35 ft worth of boards.
Answer:
x =
y²
Step-by-step explanation:
Any point (x, y ) on the parabola is equidistant from the focus and the directrix
Using the distance formula, then
= | x + 3 |
Squaring both sides
(x - 3)² + y² = (x + 3)² ← expanding both sides
x² - 6x + 9 + y² = x² + 6x + 9 ← subtract x² + 6x + 9 from both sides
- 12x + y² = 0 ( subtract y² from both sides )
- 12x = - y² ( divide both sides by - 12 )
x =
y²
The 3rd 1 am not sure though