Bisi and fibie age add up to 29. Seven years ago Bisi was twice as old as fibie. Find their present ages
Pls help
b + f = 29
b - 7 = 2(f - 7) ... b = 2 f - 7
substituting ... 2 f - 7 + f = 29
solve for f , then substitute back to find b
Let's use a step-by-step approach to solve the problem.
Step 1: Define the variables:
Let's assign the variables:
- B = Bisi's present age
- F = Fibie's present age
Step 2: Translate the given information into equations:
According to the problem, Bisi and Fibie's ages add up to 29:
B + F = 29 ......(Equation 1)
Seven years ago, Bisi was twice as old as Fibie:
(B - 7) = 2(F - 7) ......(Equation 2)
Step 3: Solve the system of equations:
To solve the system of equations (Equation 1 and Equation 2), we can use substitution or elimination method.
Option 1: Substitution method
From Equation 2, we can rearrange it to solve for F:
F = (B - 7)/2 + 7
Now substitute this expression for F into Equation 1:
B + [(B - 7)/2 + 7] = 29
simplify the equation:
B + (B - 7)/2 + 7 = 29
2B + (B - 7) + 14 = 58
2B + B - 7 + 14 = 58
3B + 7 = 58
3B = 58 - 7
3B = 51
B = 51/3
B = 17
Substitute the value of B back into Equation 1:
17 + F = 29
F = 29 - 17
F = 12
So, Bisi's present age is 17, and Fibie's present age is 12.
Option 2: Elimination method
Multiply Equation 2 by 2 to eliminate the fractions:
2(B - 7) = 4(F - 7)
2B - 14 = 4F - 28
2B - 4F = -28 + 14
2B - 4F = -14 .....(Equation 3)
Now subtract Equation 3 from Equation 1 to eliminate the variable B:
(B + F) - (2B - 4F) = 29 - (-14)
B + F - 2B + 4F = 29 + 14
- B + 5F = 43
5F = 43 + B
Since B + F = 29 from Equation 1, we can substitute B = 29 - F:
5F = 43 + (29 - F)
5F = 43 + 29 - F
5F + F = 43 + 29
6F = 72
F = 72/6
F = 12
Substitute the value of F back into Equation 1:
B + 12 = 29
B = 29 - 12
B = 17
So, Bisi's present age is 17, and Fibie's present age is 12.
Step 4: Conclusion
Therefore, Bisi's present age is 17, and Fibie's present age is 12.
To solve this problem, we need to set up a system of equations based on the given information. Let's assume Bisi's current age is "B" and Fibie's current age is "F."
From the given information, we can create the following equations:
Equation 1: B + F = 29 (The sum of their current ages is 29)
Equation 2: B - 7 = 2(F - 7) (Seven years ago, Bisi was twice as old as Fibie)
Now, we can solve the system of equations to find the values of B and F:
From Equation 1, we can rearrange it as B = 29 - F.
Substituting this value of B into Equation 2, we get (29 - F) - 7 = 2(F - 7).
Simplifying this equation, we get:
22 - F = 2F - 14
We can solve for F by moving all terms involving F to one side:
F + 2F = 22 + 14
3F = 36
Dividing both sides by 3, we find that F = 12.
Now, substituting the value of F into Equation 1, we get: B + 12 = 29.
By simplifying, we find B = 17.
Therefore, Bisi's current age is 17, and Fibie's current age is 12.