Take measurements of what you want to draw, (e.g. a simple cube that is 100 cm x 100 cm x 100 cm.)
A full scale drawing would require you to draw the cube on a paper 100 cm x 100 cm x 100 cm.
If you want to 'scale', you would then redraw using new measurements. So, a 1/10 scale drawing would mean that you would redraw the cube on paper as 10 cm x 10 cm x 10 cm.
A 1/20 scale would be 5 cm x 5 cm x 5 cm. The same concept holds for all scale drawings.
The irrational in between should be 7.8
Steps:
1. Substitute the y in 4x + 10 with -5x-10
-5x-10= 4x + 10
2. Add 5x on both sides
-10= 9x + 10
3. Subtract 10 on both sides
-20= 9x
4. Divide by 9 on both sides
5. Your answer is
X= -20/9