Question 743223
x = number of bags of apples you buy
y = number of bunches of bananas


cost of apples = number of bag x cost per bag ($4) = 4 x

cost of bananas = number of bunches x cost per bunch ($2) = 2 y

Total cost = cost of bananas + cost of apples = 2y + 4x


Total cost must be less than or equal to $12. 

Hence {{{ 2y + 4x <= 12 }}} 
or, if we divide both sides of this inequality by 2 we get 
{{{ y + 2x <= 6 }}}


The line y + 2x = 6 defines the boundary. You can draw it by working out where it hits the x and y axes.

When it passes through  the y axis, x=0 hence y + 2x = y +0 = 6. Hence the point (0,6) is on the line.

When it passes through the x axis y + 2x = 0 + 2x = 6, this x = 3. Hence the line passes through (3,0)

Draw a line from (3,0) to (0,6) and then pick a random point to the left of the line, e.g. (0,0) at (0,0) y + 2x = 0 + 2(0) = 0 which is less than 6. hence the region to the left of the line is the one which satisfies the inequality, hence shade to the right of the line.

{{{ graph( 500,500,-10,10,-10,10,  y + 2x > 6) }}}