maths

Q1. Expression not clear, cannot help.
Q2.
2^(x +2) - 2^x = 48
(2^x)(2^2) - 2^x = 48
4(2^x) - 2^x = 48
3(2^x) = 48
2^x = 16
2^x = 2^4
x = 4.
Q3.
Let cost of each egg = C.
Let price of each egg = P.
Cost of 15 egg = 15C.
Price of 12 egg = 12P.
12P = 15C
P = 15C/12 = 5C/4= 1.25C.
Therefore, % profit = (1.25C -C)/C x 100% = 0.25 x 100% = 25%.
Q4.
Let length of rectangle = m
width of rectangle = n.
Therefore, original area of rectangle = mn.
New length = m(1+ 18%) = 1.18m.
New width = n(1-30%) = 0.7n.
Therefore, new area = (1.18m)(0.7n) = 0.826mn.
Therefore, % change in area = (0.826mn - mn)/mn x 100% = -0.174 x 100%
= -17.4%. That is decreased by 17.4%.