He is false the equation should be as follows
<h3>Equation : x + y = 170 and y = 2x - 40</h3><h3>The weight of Bill is 70 pounds and weight of mark is 100 pounds</h3>
<em><u>Solution:</u></em>
Let the weight of Bill be "x"
Let the weight of mark be "y"
Given that,
Mark and Bill have a combined weight of 170 pounds
Therefore,
x + y = 170 ------- eqn 1
Mark weighs 40 pounds less than twice Bill's weight
y = 2x - 40 ------- eqn 2
<em><u>Substitute eqn 2 in eqn 1</u></em>
x + 2x - 40 = 170
3x = 170 + 40
3x = 210
x = 70
<em><u>Substitute x = 70 in eqn 2</u></em>
y = 2(70) - 40
y = 140 - 40
y = 100
Thus weight of Bill is 70 pounds and weight of mark is 100 pounds
B. Is correct I think. Hope this helped you
One formula for the lateral area is
A = 2(LW + H(L+W))
Filling in the given numbers, you have ...
A = 2((5.6 in)·(4.3 in) + (10 in)·(5.6 in + 4.3 in))
= 2(24.08 in² + 99 in²)
= 246.16 in²
