Answer:
b)Add the equations to eliminate x.
Step-by-step explanation:
y= x+20
y= - x+2
Result of the addition: (-x cancels x)
2y = 22
y =11
11=x +20 -9 = x
11=9+2
11 = -9 +20
Use Conects it got all the math questions n got the answer to questions ahead of the one u looking for
Answer:
1. 43/36
2. 1/2
Step-by-step explanation:
1. 7/9 + 5/12
= LCM of 9 and 12 is 36
= 28/36 + 15/12
= (28 + 15) / 36
= 43/36
2. 21/24 - 3/8
= LCM of 24 and 8 is 24
= 21/24 - 9/24
= (21 - 9) / 24
= 12/24
= 1/2
Answer:
Internal validity
Step-by-step explanation:
The internal validity here is weak
Internal validity describes the extent to which an evidence weighs the cause and effect claim. In this study, the internal validity that brought about failure in the new exam is mainly due to the environment where the exam was written and not the new exam itself.
So this validity is weak in claiming that the new exam is not a good substitute for the old exam.
Putting them in the same good environment might help the researchers to draw a better conclusion.