Answer:
(-3, 0)
Step-by-step explanation:
Let's solve this system using the elimination by addition/subtraction method. Begin by writing the two equations one above the other:
5x +2y =-15
2x - 2y =-6
Notice that the y terms cancel each other out:
5x +2y =-15
2x - 2y =-6
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7x = -21
Dividing both sides by 7 results in x = -3.
Subbing -3 for x in either of the given equations leads to finding y:
5(-3) + 2y = -15, or -15 + 2y = -15. This results in 2y = 0, or y = 0.
The solution is (-3, 0).
Answer:
a rectangle is twice as long as it is wide . if both its dimensions are increased 4 m , its area is increaed by 88 m squared make a sketch and find its original dimensions of the original rectangle
Step-by-step explanation:
Let l = the original length of the original rectangle
Let w = the original width of the original rectangle
From the description of the problem, we can construct the following two equations
l=2*w (Equation #1)
(l+4)*(w+4)=l*w+88 (Equation #2)
Substitute equation #1 into equation #2
(2w+4)*(w+4)=(2w*w)+88
2w^2+4w+8w+16=2w^2+88
collect like terms on the same side of the equation
2w^2+2w^2 +12w+16-88=0
4w^2+12w-72=0
Since 4 is afactor of each term, divide both sides of the equation by 4
w^2+3w-18=0
The quadratic equation can be factored into (w+6)*(w-3)=0
Therefore w=-6 or w=3
w=-6 can be rejected because the length of a rectangle can't be negative so
w=3 and from equation #1 l=2*w=2*3=6
I hope that this helps. The difficult part of the problem probably was to construct equation #1 and to factor the equation after performing all of the arithmetic operations.
Answer:#2
Step-by-step explanation:
Answer:
840 cm³
Step-by-step explanation:
Cut the prism into two cuboids.
The first cuboid has dimensions of 4 cm × 6 cm × 5 cm
The height is 4 cm, the width is 5 cm and the length is 6 cm.
The second cuboid has dimensions of 15 cm × 6 cm × 8 cm.
The height is 8 cm, the width is 6 cm and the length is 15 cm.
The formula for the volume of the cuboid is l×w×h.
Length × Width × Height
The first cuboid has a volume of:
4 cm × 6 cm × 5 cm
= 120 cm³
The second cuboid has a volume of:
15 cm × 6 cm × 8 cm
= 720 cm³
Add the volumes of the two cuboids.
720 cm³ + 120 cm³
= 840 cm³
The volume of the prism is 840 cm³.
Between 4 and 5 is the spare root of 18