Explanation:
function 1 :
simple, you put 3 into every place of x and then calculate.
y = -4×3 + 2 = -12 + 2 = -10
function 2 :
the only one where we need to think a little.
so, x = 3.
from the center of the coordinate axes we go on the x-axis to 3.
from there we go up out down to intersect the line. then we look to the left to the y-axis and see what value we have there : -1
y = -1 when x = 3
function 3 :
the solution is already written there in full sight.
input = 3.
so, we look in the table. where is the line with input = 3 ?
it is the last but one line. what value is in the output column of that line ? -3
output = -3