7x+1 + 4x-3 = 42
11x-2=42
11x=44
Divide by 11 on both sides which equals:
x=4
To find the length of DE just plug 4 in for x into the equation:
(7x+1) —> 7(4)+1= 29
29 is the length of DE
Then plug in 4 to EF’s equation:
(4x-3) —> 4(4)-3=13
13 is the length for EF
29+13= 42
So in the end, your answer will be 29.