Answer:
10x + 12 and 6x² + 11x - 7
Step-by-step explanation:
The perimeter (P) of a rectangle is calculated as
P = 2l + 2w ( l is length and w is width )
= 2(2x - 1) + 2(3x + 7) ← distribute parenthesis
= 4x - 2 + 6x + 14 ← collect like terms
= 10x + 12
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The area (A) of a rectangle is calculated as
A = lw
= (2x - 1)(3x + 7) ← expand using FOIL
= 6x² + 14x - 3x - 7 ← collect like terms
= 6x² + 11x - 7
A) 122 in^2, this is because 3 x 7 x 2= 42, 4 x 7 x 2= 56, 3 x 4 x 2= 24, once you add up all the sums it equals 122
Answer:
28π cm²
Step-by-step explanation:
The surface of a cylinder is given by the formula:
where r is the radius of the base, and h is the height.
Using the image, we can find that the radius of the cylinder would be 2 cm, and the height would be 5 cm.
Now, to find the surface area of the cylinder, we would have to plug in 2 for r (the radius of the base) and 5 for h (the height of the cylinder) into the formula for the surface area of a cylinder.
Now we plug in 2 for r and 5 for h for the equation for the surface area of a cylinder:
2π(2)(5) + 2π(2)² = 20π + 2π(4) = 20π + 8π = 28π
Remember, the radius and the height are given to us in cm, and w are solving for surface area, so the answer should be in cm² (square centimeters).
The surface area of the cylinder would be 28π cm².
28π cm² would be an exact answer. For the approximate answer, plug in 3.14 (most math classes use 3.14 to approximate π) for π.
I hope you find this helpful. :)
