How much part can sally paint in an hour ?
a ÷ 7 = a/7
And what about Steve ?
a ÷ 9 = a/9
Where, a is the total area of the room.
So, let the time taken by both of them to paint the room together be 't'
So,
t(a/7 + a/9) = a
t(9a/63 + 7a/63) = a
t(16a/63) = a
t = 63/16 ≈ 4 hr
Use of distributive property will be
(30 x 5) + (9 x 5)
21. the error for x - 28 = 375 is not 347 is because the student subtracted both sides by 28. 347 - 28 is 319 not 375. One must add 28 to both sides of -28 and 375. The -28 and 28 is zero. 375 + 28 = 403.
22. The next three terms are 0.93, 1.02, and 1.11. The rule in the number pattern is one must add 0.09.
2b^2. This is because you have a positive a^2 and a negative so they cross it one another so it just leaves the b’s.
Answer:
circumference of the circle=2πr
5.7 cm
