Since both trapezoids are similar, so LMNO is a scaled version of QRST by some magnitude
so we can easily use the concept of ratios to find x
in other words: x÷2=6÷5
so x=6×2÷5=12/5=2.4
x=2.4
Remaining water in the tank is (19/2-19/3) gallons = 57-38/6=19/6 =3 1/6 gallons
D) because the first equation*3-the second equation*;
the left side=0, the right side = 36
2(c+7)=2c+14
Use distributive property
2*c +2*7
2c+14=2c+14
Hope it helps!