2x + y = 20
-5y = -6x + 12
To use the substitution method, first isolate one of the variables in one of the equations.
Isolate the "y" in the first equation (because it is the easiest to isolate), and substitute it into the second equation:
2x + y = 20 Subtract 2x on both sides
y = 20 - 2x
-5y = -6x + 12 (since y = 20 - 2x, you can substitute 20 - 2x into y)
-5(20 - 2x) = -6x + 12 Multiply -5 into (20 - 2x)
-100 + 10x = -6x +12 Add 100 on both sides
10x = -6x + 112 Add 6x on both sides
16x = 112 Divide 16 on both sides
x = 7
Now that you have found x, you can substitute 7 into x for one of the original equations:
2x + y = 20
2(7) + y = 20
14 + y = 20 Subtract 14 on both sides
y = 6
-5y = -6x + 12
-5y = -6(7) + 12
-5y = -42 + 12
-5y = -30 Divide -5 on both sides
y = 6
x = 7, y = 6
Step-by-step explanation:
Let grandson's age be x.
Let grandpa's age be y {equation : y = 8+5x}
so,
x + y = 88
or, x + 8+ 5x = 88 (substituting the value of y)
or, 6x + 8 =88
or, 6x = 88-8
or, 6x = 80
or, x = 80/6
so, x = 13.33
so grandson's age = 13.33
grandpa's age = 8 + 5x = 8 + (5×13.33) = 74.65 yrs
An ellipse is divided into two axes, the longer axis is the
major axis and the shorter axis is the minor axis. The length of the major axis
of an ellipse is equal to the sum of two distance: the distance between any
point on the ellipse and one on focus and the distance between the same point
and the other focus. The focus is the point that helps define an ellipse and
every ellipse has two foci. These two distance are also called the red line
segment and blue line segment. Given 6 for red line segment and 4 for blue line
segment therefore, the length of the major axis of the ellipse is 10.
Answer:
9 square kilometers
Step-by-step explanation:
Let's round the width to 2.0 kilometers, and round the length to 4.5 kilometers.
We know that area is length times width, so
A = lw
A = 2.0*4.5
<u>A = 9.0 square kilometers</u>
If we do this on the calculator, it's around 9.36 square kilometers, so our estimate was good.
