·
=
. This can be simplified to 5x
, because √50 simplifies to 5√2 (since 5x5x2 equals 50) and the square root sign takes x² from x³ and turns it into just x.
(₋4)²
how i got it -
1st i used the sum-product pattern
x² - 8x + 16
x² -4-4+16
then, found the common fact from the two pairs
x² - 4 - 4 + 16
(-4) - 4(-4)
rewrite in factored form
(x-4)-4(-4)
(-4) (-4)
combine to a square
(-4) (-4)
Lateral faces are all the sides of the prisms EXCEPT the bases, which are the sides on the top and bottom. To find the area of the lateral faces we can use the formula: perimeter x height.
perimeter = 2 (6 + 8) = 2 x 14 = 28
height = 14
area of the lateral faces = perimeter x height = 28 x 14 = 392
Hope this helps!
Answer:
Train A - 50 miles per hour
train B - 30 miles per hour
Step-by-step explanation:
Let x mph be the speed of the train B, then the speed of the train A is (x+20) mph.
In 3 hours,
- train A travels 3(x+20) miles
- train B travels 3x miles
In total, they covered the distance of 240 miles, so
![3(x+20)+3x=240\ \ \ \text{[Divide by 3]}\\ \\x+20+x=80\\ \\2x=80-20\\ \\2x=60\\ \\x=30\ mph\\ \\x+20=30+20=50\ mph](https://tex.z-dn.net/?f=3%28x%2B20%29%2B3x%3D240%5C%20%5C%20%5C%20%5Ctext%7B%5BDivide%20by%203%5D%7D%5C%5C%20%5C%5Cx%2B20%2Bx%3D80%5C%5C%20%5C%5C2x%3D80-20%5C%5C%20%5C%5C2x%3D60%5C%5C%20%5C%5Cx%3D30%5C%20mph%5C%5C%20%5C%5Cx%2B20%3D30%2B20%3D50%5C%20mph)
