<span>-4 + -7 (-2)
= -4 + 14 (a negative multiplies a negative equal positive)
= 10</span>
(5x+1)² = 7; expand: 25x² + 10x +1 = 7 or 25x² + 10x -6 = 0
Solve this quadratic for x:
x = [-b + √(b² - 4ac)]/2a and x = [-b - √(b² - 4ac)]/2a
Plug the values and you'll find :
x = (- √7 - 1)/5 (answer C)
x = (+√7 -1)/5 (answer E)
Answer:
The number is 6.25
Explanation:
Assume that the number we are looking for is x
First, we will set up the equations as follows:
1- Subtract 1.05 from the number (assume the result is y):
x - 1.05 = y
2- Multiply the difference by 0.8 (assume the product is z):
0.8(y) = z
3- add 2.84 to the product (assume the result is w):
z + 2.84 = w
4- divide the sum by 0.01, the quotient is 700:
w / 0.01 = 700
Now, we will work backwards as follows:
4) w / 0.01 = 700
w = 0.01 * 700
w = 7
3) z + 2.84 = w
z + 2.84 = 7
z = 7 - 2.84
z = 4.16
2) 0.8y = z
0.8y = 4.16
y = 4.16 / 0.8
y = 5.2
1) x - 1.05 = y
x - 1.05 = 5.2
x = 5.2 + 1.05
x = 6.25
Hope this helps :)
Answer: Total area 2800 sq.yards
Step-by-step explanation:
First roof
2 rectangles and 2 trangles
for rectangles area = b*h
then area of one rectangle = 20*30 = 600 sq.yards
We have 2 rectangles then 2 * 600 = 1200 s. yards
for triangles area 1/2 b*h
Then area of one triangle = 0.5* 5*20 = 50 sq.yards
We have 2 triangles then 2 * 50 = 100 sq.yards : 1300 sq.yards
Total area first roof = 1300 sq.yards
Second roof
Area of rectangle = b*h = 25*60 = 1500sq.yards
Total area second roof = 1500 sq.yards
