Find the value of: (x + y) - (x - y) when x 2 and y= -1
(m + n) - 3mn (m + n) when m = 3 and n = -2
(b)
Solve:
(a) If ab=2, bc = 6 and ca = 3 then find the value of a.
(b) If a + b = 5, b+c=6 and c + a = 7 then find the value of a.
[ Hint: Adding them, a +b+b+c+c+a=5+6+7)
Math Links Book 7

Aaron invested a total of $4,100, some in an account earning 8% simple interest, and the rest in an account earning 5% simple interest. how much did he invest in each account if after one year he earned $211 in interest? select one: a. $200 at 8%, $3,900 at 5% b. $3,200 at 8%, $900 at 5% c. $900 at 8%, $3,200 at 5% d. $3,900 at 8%, $200 at 5%