Answer:
x = 5.4
Step-by-step explanation:
(This question has already been answered, but both of the incorrect ones were deleted, so for future reference...)
Fig A is a scale image of Fig D. These two quadrilaterals are similar, and thus, the side lengths of corresponding sides are proportional. Set the proportion x/3 = 7.2/4 (you could alternatively write it as x/7.2 = 3/4 but for the simplicity's sake, and assuming anyone who has this problem would already know how to solve proportions like these...)
7.2/4 = 1.8
so
x/3 = 1.8
now multiply both sides by 3 to get x = 5.4
By combining like terms, the answer is a
Sum = 20(1-(1/4)^5) / (1-1/4) = 26.64
Answer:
x = ± sqrt(43)
Step-by-step explanation:
2x^2 - 28 = x^2 + 15
Subtract x^2 from each side
2x^2-x^2 - 28 = x^2-x^2 + 15
x^2 -28 = 15
Add 28 to each side
x^2 - 28 +28= 15+28
x^2 = 43
Take the square root of each side
sqrt(x^2) = ± sqrt(43)
x = ± sqrt(43)