Answer:
subtract -3
Step-by-step explanation:
–3 + 4x = 9
Add 3 to each side
This is the same as subtracting -3
-3 + 4x - (-3) = 9 - (-3)
4x = 9 +3
4x = 12
Answer:
1/6 meters
Step-by-step explanation:
Let the side length be x.
Then the area of the square = x^2
∴ x^2 = 1/36
√(x^2) = √(1^2 / 6^2)
x = 1/6
Therefore, the side length is 1/6 meters.
Hope it helped you!!!
Answer:
225 m²
Step-by-step explanation:
If W is the width of the rectangle, and L is the length, then:
60 = 2W + 2L
A = WL
Use the first equation to solve for one of the variables:
30 = W + L
L = 30 − W
Substitute into the second equation:
A = W (30 − W)
A = 30W − W²
This is a parabola, so we can find the vertex using the formula x = -b/(2a).
W = -30 / (2 × -1)
W = 15
Or, we can use calculus:
dA/dW = 30 − 2W
0 = 30 − 2W
W = 15
Solving for L:
L = 30 − W
L = 15
So the maximum area is:
A = WL
A = (15)(15)
A = 225
It can help because 9×4 =36, and 9×8=72. if you divide 72 by 2 you get 36 which is the answer to 9 ×4. basically because nine is the same in both problems you are multiplying by 4 (and you know 4 is half of 8) you can assume that multiplying the sum of 4 and 9 that you will get the sum of 8 and 9.
