Answer:
Nico invest [tex]\$2,100[/tex] at 7% and [tex]x=\$900[/tex] at 3%
Step-by-step explanation:
we know that
The simple interest formula is equal to
[tex]I=P(rt)[/tex]
where
I is the Final Interest Value
P is the Principal amount of money to be invested
r is the rate of interest
t is Number of Time Periods
in this problem we have
At 7%
[tex]t=1\ years\\ P=\$x\\r=0.07[/tex]
substitute in the formula above
[tex]I1=x(0.07*1)[/tex]
[tex]I1=0.07x[/tex]
At 3%
[tex]t=1\ years\\ P=\$(x-1,200)\\r=0.03[/tex]
substitute in the formula above
[tex]I2=(x-1,200)(0.03*1)[/tex]
[tex]I2=0.03x-36[/tex]
The total interest is equal to
I=I1+I2
I=$174
substitute
[tex]174=0.07x+0.03x-36[/tex]
[tex]0.10x=174+36[/tex]
[tex]0.10x=210[/tex]
[tex]x=\$2,100[/tex]
[tex]x-1,200=2,100-1,200=\$900[/tex]
therefore
Nico invest [tex]\$2,100[/tex] at 7% and [tex]x=\$900[/tex] at 3%
