What is the value of X

A 21
B 41
C 20
D 22

22

Step-by-step explanation:

Let the bottom be y for the small triangle

So the total length of the bottom is 2y

We can use ratios to solve

x-1       1y

=

42          2y

Canceling the y's

x-1       1

=

42          2

Using cross products

2(x-1) = 42

Divide by 2

x-1 = 21

Add 1 to each side

x-1+1=21+1

x = 22

step-by-step explanation:

step 1: solve one of the equations for one of the variables. let's solve the first equation for y:

step 2: substitute that equation into the other equation, and solve for x.

step 3: substitute x = 4 x = 4 x=4 into one of the original equations, and solve for y.