3. To combine the equations and solve for one of the variables, you need to eliminate the other variable. How can you change one equation so that one variable is eliminated when the two
equations are added? Explain and write the new equation. (3 points: 2 for your explanation and
1 for the equation)

If we multiply equation 2 with -6 and add both equations, we can eliminate variable y. The equation is given and solved below.

Step-by-step explanation:

The equations given are:

12x+6y=120

4x+y=30

We need to find How can you change one equation so that one variable is eliminated when the two  equations are added?

Let:

If we multiply equation 2 with -6 and add both equations, we can eliminate variable y.

Solving

So, we eliminated the variable y and found the value of x.

Now Putting value of x in any of above equations we can find value of y.

So, we get value of y=10

d) by the cross product property, ab^2 = bc multiplied by ad

step-by-step explanation:

we are given

in the given triangle abc

angle a is 90° and segment ad is perpendicular to segment bc

we can see that

triangle(abc) and triangle(abd) are similar because they have common side and same angle (90 degree)

so, triangles(abc) and abd are similar

since, they are similar

so, the ratio of their sides must be equal

we get

now, we can cross multiply

and we get

so, this could be step to prove it

2.2°  

step-by-step explanation:

let θ = the angle of elevation.

tanθ =77/2020

tanθ = 0.038 12

      θ = tan⁻¹0.038 12

      θ = 2.2°