An amount of $700 is invested partly at 8% and partly at 10%. the yearly income from both investments is $64. the amount invested at 8% is k dollars. what is the value of k?

A8% is X
10% is 700-X

X(.08)+ .10(700-X)= 64
.08x+ 70-.10X=64
-.02X+70=64
-70=-70
-.02x= -6
Divide by -.02
X= 300

Answer $300 was invested at 8%

Check 300 times .08= 24. 700-300=400 times .10 = 40 and 24+40=64

The linear equation is: y=ax+b

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.