<u>Answer:</u>
2x²+6x-9=0
<u>Step-by-step explanation:</u>
2x(3+x)=9
6x+2x²=9
2x²+6x-9=0
Answer: each of the students took 1/4 of an eraser home.
Step-by-step explanation:
On the last period our teacher had 1/2 of an eraser left. She gave it equally to 2 students. This means that the amount of eraser that each student takes home would be
(1/2)/2 = 1/2 × 1/2 = 1/4 of an eraser. Converting to decimal, it becomes 0.25 of an eraser.
Answer:
x + 2y = 12
Step-by-step explanation:
Using the formula, write in standard form. If you know the formula.
1. x^2 + 13x + 36 = 0
using powerful & time-sparing quadratic formula :
delta = 13^2 - 4*1*36 = 25 = 5^2
x1 and x2 = (-13 -/+ 5)/2 = -9 and -4
x^2 + 13x + 36 = (x+9)(x+4)
2. other way : complete the square
b^2 + 12b + 32 = b^2 + 2*6b + 6^2 - 6^2 + 32
b^2 + 12b + 32 = (b+6)^2 - 4
b^2 + 12b + 32 = (b+6-2)(b+6+2) = (b+4)(b+8)
3. other way : -4 "ovious" solution : (-4)^2 - (-4) -20 = 0
so the other is : -4 . a2 = -20/1 ---> a2 = 5
a^2 - a - 20 = (a-5)(a+4)
Step-by-step explanation:
the the height should be 16 cm I used the Pythagoras theory thank you.
