8P = A because there are 8x apples per x pear, so to make it equal we must multiply pears by 8. P+A = 981. replacing "A" in the second equation with "8P" to get P+8P=981=9P divide both sides by 9 to get 109 pear trees. knowing this we can get 981-109=A=872 apple trees. the problem asks for A-P which we can replace the numbers to get (872)-(109)=763 more trees
The function that we have in this is f(x) = 4x. We can see this in 4 * 4 = 16, 5 * 4 = 20 and 6 * 4 = 24. Therefore, following the pattern, 7 * 4 = 28.
