With these substitution problems;
A=3b-4
A+b=16
A=3b-4
A+b=16
-
Okay you have to focus on the 2nd problem you have: A+b=16 what plus what gives you the answer 16, but those two numbers that have to equal 16 also have to make A=3b-4 True.
Example:(but no answer you have to figure it out m8)
Since A and B are variables they can represent any number possible.
So For A you can use the number 10 (A=10)
and for B you can use the number 6 (B=6)
So 10+6=16 that's true, so does the 10 and 6 make problem 1 true?
Replace the A and B in the first problem to see if it makes it true.
A = 10 so
10=3b-4
and B = 6 so
10=3x6-4
Sum all of that up starting with Multiplication, and then subtraction
3x6= 18 and then 18 - 4 = 14
So the numbers I used for A and B were wrong because remember that A = 10 not 14 so keep trying numbers and you will solve it. And by next time you will have learned how to do it and won't need to wait 20 minutes to get an answer on yahoo.
Hope this helped m8.
Example:(but no answer you have to figure it out m8)
Since A and B are variables they can represent any number possible.
So For A you can use the number 10 (A=10)
and for B you can use the number 6 (B=6)
So 10+6=16 that's true, so does the 10 and 6 make problem 1 true?
Replace the A and B in the first problem to see if it makes it true.
A = 10 so
10=3b-4
and B = 6 so
10=3x6-4
Sum all of that up starting with Multiplication, and then subtraction
3x6= 18 and then 18 - 4 = 14
So the numbers I used for A and B were wrong because remember that A = 10 not 14 so keep trying numbers and you will solve it. And by next time you will have learned how to do it and won't need to wait 20 minutes to get an answer on yahoo.
Hope this helped m8.
-
subtract b from a+b=16 to get a=16-b, then make 3b-4=16-b (they both equal the same thing so the equal each other). then subtract 16-4 to get 3b=12-b, then subtract 3b-b to get 12=2b, then divide 12/2 so b=6 is your answer