Solve the system of equations by elimination
3x+4y=31
2x-4y=-6

x = 5 and y = 4

Step-by-step explanation:

In elimination method we solve a system of two variable equations by eliminating one variable by operating the equations.

Given system of equations,

3x + 4y = 31  (1)

2x - 4y = -6 (2),

Equation (1) + equation (2),

3x + 2x = 31 - 6

5x = 25

x = 5

From equation (1),

3(5) + 4y = 31

15 + 4y = 31

4y = 16

y = 4

Hence, the solution of the given equations is, x = 5, y = 4

answer: i don't understand it

step-by-step explanation: sorry

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4