I think the answer is 120.
Answer:
<u>41 years ago</u>
Step-by-step explanation:
Let the no. of years ago be x.
Then, the equation we need would be :
=> 80 - x = 3(54 - x)
=> 80 - x = 162 - 3x
=> 2x = 82
=> x = 41
Sally's mother was 3 times her age <u>41 years ago</u>
Checking
=> Sally = 54 - 41 = 13
=> Mom = 80 - 41 = 39
=> 13 x 3 = 39 [∴Verified]
Compatible numbers is used to find estimate to a sum. The numbers are chosen because its 'simplicity' when they are multiplied, divided, added or subtracted.
Estimate one:
We can decrease the value 1322 to 1320 and 18 to 15
Then do the sum = 1320÷15 = 88
This estimate is not far from the actual answer 1322÷18 = 73.44..
Estimate two:
We can increase 1322 to 1330 and 18 to 20
Then do the sum 1330÷20=66.50
This estimate is also not far from the actual answer 73.44...
Answer: Angle A is 115 degrees
Step-by-step explanation:
In triangle ABC, the measure of angle A is seven more than four times measure of angle B. This means that
Angle A = 4(Angle B) + 7
The measure of angle C is eleven more than measure of angle B. This means that
Angle C = Angle B + 11.
The equations are
A = 4B + 7 - - - - - - - - 1
C = B + 11 - - - - - - - - - - 2
Recall that the sum of the angles in a triangle is 180 degrees. This means that
A + B + C = 180 degrees
Substituting equation 1 and equation 2 into A + B + C = 180, it becomes
4B + 7 + B + B + 11 = 180
6B + 18 = 180
6B = 180 - 18 = 162
B = 162/6 = 27 degrees
Substituting B = 27 into equation 1, it becomes
A = 4×27 + 7 = 108 +7
A = 115 degrees
Substituting B = 27 into equation 2, it becomes
C = 27 + 11
C = 38 degrees
Sum of the angles is 115 + 27 + 38 = 180
