She is correct! This is so because 3 goes into .9 by .3 times. Hope this helped!
X-0.075x=7400
Solve for x
0.925x=7400
x=7,400÷0.925
X=8,000
by the use of elimination method
make all coefficients of subject to be eliminated similar..by multiplying the coefficients with one another
for eqn(i)
5(-10y+9x=-9)
-50y+45x=-45
for eqn(ii)
9(10y+5x=-5)
90y+45x=-45
-50y+45x=-45
90y+45x=-45
...subtract each set from the other...
we get
-140y+0=0
y=0
from eqn(i)
10y+5x=-5
0+5x=-5
x= -1
Use the formula A=p(1+r)^n
where
A= value of investment
r= rate
n= time period
p= amount invested
in this question
r= 5.75% but compounded quarterly means divide this by 4
r= 23/1600
n=7*4
n=28
p= $1200
A=1200(1+23/1600)^28
A= $1789.54
Therefore the value of her investment in 7 years is $1789.54
