Question 7: Solve this system

A.(15, 10)
B.(-15, 10)
C.(-10, 25)
D.(10, 15)

D. (10, 15)

Step-by-step explanation:

Hi there!

We are given the following system:

+y=20

x+4y=70

And we want to solve it (find the values of x and y).

Let's use substitution for this problem, where we will isolate one variable on one side, while the other side contains an expression with the other variable. Then, we use the expression to solve for the variable that the expression contains, then use the value of that variable to solve for the aforementioned isolated variable.

Subtract from both sides in the first equation

y=20-

Now substitute 20- as y in x+4y=70

x+4(20-)=70

Do the distributive property

x+80-2x=70

Combine like terms on the left

-x+80=70

Subtract 80 from both sides

-x=-10

Multiply both sides by -1

x=10

We found the value of x. Now let's use that value to find what y is

Since we know that y=20- and x=10, we can substitute 10 as the value of x to solve for y

In that case,

y=20-(10)

Multiply

y=20-5

Subtract

y=15

The answer is x=10, y=15, or as a point, (10, 15), aka D

Hope this helps!

b. an equilateral triangle inscribed in a circle

step-by-step explanation:

we are given the figure of two circles having a triangle inside.

now, we know that,

"when a figure is lying inside an another figure, then the outside figure is known as circumscribed figure and the figure lying inside is referred to as the inscribed figure".

as we see that, the circles are containing the triangle completely.

thus, the circles are the circumscribed figures and the triangle is the inscribed figure.

hence, we get, 'an equilateral triangle is inscribed in a circle'.

chase is right because he already been to the swings and he know how far it will be to get there

step-by-step explanation: