If f : R→ R is a function defined by
f(x)={2x if x⩾0−3x if x<0
Find the value of f(-10).f(2) + f(-1) – f(3).
f(x)={2x if x⩾0−3x if x<0
(f(-10) = -3(-10) = 30
f(2) = 2(2) = 4
f(-1) = -3(-1) = 3
f(3) = 2(3) = 6
f (-10).f(2) + f(-1) – f(3) = (30)(4) + 3 – 6
= 120 – 3 = 117