Complementary angels are two angles that equal 90 when added so S degrees + Z degree = 90 degrees or 50 degree + 40 degree = 90 so forth 4B in comments
She earns 20 dollars as a carpenter and 25 dollars as a blacksmith
b+c=30 hours since she works 30 hours a week
25b+20c=690 since she earns 690 dollar totally and earns 25 dollars an hour as a blacksmith and 20 dollars an hour as a carpenter
lets multiply b+c=30 by -20
-20b-20c=-600
if we substract that from
25b+20c=690
5b=90
b=18 she worked as a blacksmith for 18 hours
32.5 square feet. If you do the area formula “A=5v13(13) over 2”
