Answer:
9a + 6b and 5c - 3d
Step-by-step explanation:
(a)
4a + 7b + 5a - b ← collect like terms
= (4a + 5a) + (7b - b)
= 9a + 6b
(b)
6c + 4d - c - 7d ← collect like terms
= (6c - c) + (4d - 7d)
= 5c - 3d
Answer:
a. 5.26
Step-by-step explanation:
As, the standard deviation of the distribution of the difference between mean is 0.76 so the t score will be simply calculated by dividing the difference of means by standard deviation of the distribution of the difference between mean as hypothesized difference is zero.
t score=Xbar A- Xbar B/Sd of difference of means
t score=55-51/0.76
t score=4/0.76=5.26
