Answer:25,000 in 2 years at annual compound interest, if the rates for the successive years be 4% and 5% per annum respectively is: (1) Rs. 30,000 (2) Rs. 26,800 fa) Rs.
A=P[1+
100
r
]
n
⇒ A=Rs.25,000×(
100
106
)
3
⇒ 25,000×
50
53
×
50
53
×
50
53
⇒ A=Rs.29,775.40
⇒ CI=A−P
⇒ Rs.29,775.40−Rs.25,000
∴ CompoundInterest=Rs.4775.40.
Substitution is where we first Isolate one of the unknowns, express it in terms of the other unknown, and replace the isolated unknown with the other unknown in another equation. So that each time we only need to deal with one unknown. I think you'll get a better idea here:
First name these 2 equations with 1 and 2.
4x + 5y = 7 (1)
y = 3x + 9 (2)
Since y is already isolated in (2), so we can skip the isolation step and continue to substitute.
Substitute (2) into (1).
4x + 5(3x+9) = 7
Expand.
4x + 15x + 45 = 7
Group.
19x + 45 = 7
Shift +45 to the other side and turn it into -45.
19x = 7 - 45
19x = -38
Shift x19 to the other side, turn it into /19.
X = - 38/19
X = - 2
Now we solved x already, we can just substitute x= - 2 back to equation (2).
y = 3(-2) + 9
y = - 6 + 9
y = 3
So, the answers are
x = - 2
y = 3
-4fx + -8f - 5
I’m pretty sure that’s correct, might be wrong double check with someone else
4g+3(-3+4g)=1-g
Distribute the 3(-3+4g)
4g-9+12g=1-g
Add 4g and 12g
16g-9=1-1g
Add 1g and 16g (variables always have an invisible 1 in front)
17g-9=1
Add 9 and 1
17g=10
Divide both sides by 17 and the answer is g=10/17
The correct answer is 600. For area do you Base times height which is 20×30 which equals 60.