Answer:
Total surface = 102.4 cm^2 (second answer in the list of options)
Step-by-step explanation:
Notice that we need to add the surface of 4 rectangles, two have smaller sizes than the other two. A pair of rectangles are 7.2 cm x 4 cm = 28.8 cm^2, while the other pair has 7.2 cm x 2 cm = 14.4 cm^2
There are also two equal bases each one of size 4 cm x 2 cm = 8 cm^2
Now we add two of each of the individual surfaces discussed above to complete the total surface area:
2 * 28.8 + 2 * 14.4 + 2 * 8 = 102.4 cm^2
which agrees with the second answer option provided.
The correct answer is y = 11
because:
2y + 7 = 3y − 4
−y + 7 =−4
Subtract 7 from both sides.
−y + 7 − 7 = − 4 − 7
−y = −11
Divide both sides by -1.
y = 11
The first one is -763.1 and the second one is -24