In order to do this you have to substitute b with 9 and get 3a+9=54, now subtract 9 from both sides to leave a by itself and get 3a=45, now divide 3 in both sides to leave a by itself and get a=15
Hope this helps
Answer:
45 is answer I guess cuz my teacher taught me just like that
Answer:
42x² - 3x - 9
the area of the garden is:
(7x + 3)(6x - 3)
= 42x² - 21x + 18x - 9
= 42x² - 3x - 9
The answer is C) 3 x 10^4