2(2x) + 1x = 40 or 4x + 1x = 40 is the result of combining by substitution
<em><u>Solution:</u></em>
Given that we have to combine 2y + 1x = 40 and y = 2x using substitution method
The substitution method for solving systems of equations involves expressing one variable in terms of another, thus removing one variable from an equation.
<em><u>Given equations are:</u></em>
2y + 1x = 40 -------- eqn 1
y = 2x ----------- eqn 2
We can substitute eqn 2 in eqn 1
Which means, substitute y = 2x in place of y in eqn 1
2(2x) + 1x = 40
4x + 1x = 40
5x = 40
x = 8
From eqn 2,
y = 2(8)
y = 16
Thus by combining using substitution method we found the solution
The answer is A because when a question asks how much is left it typically means that you will need to subtract.
This would be 12 - 12*cos(30) = 12 - 6

= 1.608 ft off the ground.
Try this solution:
for the circle A: circumference=6π, area=9π
for the circle B: circumference=12π, area=36π
PS. formula for circumference is 'L=2πr', for area is 'S=πr²'.