Answer:
a = 8
Step-by-step explanation:
45° - 45° - 90° triangle
1 - 1 - √2
8 - 8 - √8
w-(-3)=7
Pretend that there is a -1 in front of the bracket
w-1(-3)=7
Mutiply the bracket by -1
(-1)(-3)=3
w+3=7
Move +3 to the other side. Sign changes from +3 to -3.
w+3-3=7-3
w=4
Answer: w=4
$$3000-$1200=$1800
take $1800÷$40=45
6