Evaluate the expression 5^2(72-45) / 5
1 answer:
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Answer:
Step-by-step explanation:
1. Let the number be x
x^2 + 4x = 21
x^2 + 4x - 21 = 0
Solve the quadratic equation using factorization method
x^2 - 3x + 7x - 21 = 0
x(x - 3) + 7(x - 3) = 0
(x - 3)(x+7) = 0
x - 3 = 0 x + 7 = 0
x = 3 x = -7
The number is either 3 or -7
2. Same solution as number 1
3. Let
Width = x
Length = 2x - 3
Area of the rectangle = 9 square ft
Area of a rectangle = length × width
9 = (2x - 3) (x)
9 = 2x^2 - 3x
2x^2 - 3x - 9 = 0
Solve using quadratic formula
a = 2
b = -3
c = -9
x = -b +or- √b^2 - 4ac / 2a
= -(-3) +or- √(-3)^2 - 4(2)(-9) / 2(2)
= 3 +or- √ 9 - (-72) / 4
= 3 +or- √9 + 72 / 4
= 3 +or- √81 / 4
= 3 +or- 9 / 4
x = (3 + 9)/4 or (3 - 9) / 4
= 12 / 4 or -6 / 4
x = 3 or -3/2
Width can not be a negative value
So,
Width = x = 3 ft
Length = 2x - 3
= 2(3) - 3
= 6 - 3
= 3ft
2.if the sum of the square of the number and 4 time that number is 21 the what is the number?
3. the length of the rectangle is 3 less than twice the width. if the area is 9 square ft, the length and width of the rectangle.
4.given the figure below. find the area of the shaded part of the rectangle if the area of the big but angle is 6 times the area of the unshaded rectangle
Unshaded area
Length = 2x
Width = x
Shaded area
Length = (2x+3)
Width = (x+3)
Area of the shaded area = 6 × the unshaded area
(2x) (x) = 6(2x + 3)(x+3)
2x^2 = 6(2x^2 + 6x + 3x + 9)
2x^2 = 12x^2 + 36x + 9x + 54
2x^2 = 12x^2 + 45x + 54
12x^2 + 45x + 54 - 2x^2 = 0
10x^2 + 45x + 54 = 0
Answer:
Step-by-step explanation:
Equation of a line:
The equation of a line has the following format:
In which m is the slope, and b is the y-intercept(value of y when x = 0).
In this question:
We have that when . So the line is given by:
Finding the slope:
We have two points in the line, which are (-3,-3) and (3,-1). The slope is given by the change in y divided by the change in x. So
Change in y: -1 - (-3) = -1 + 3 = 2
Change in x: 3 - (-3) = 3 + 3 = 6
Slope:
Solution to the inequality:
The solution to this inequality is all the points above the dashed line, which means that the dashed line is not part of the solution. So