## safia21 5 years ago algebra can you help me with # 2 and # 3 thanks

1. safia21

2. anonymous

the cooking one?

3. safia21

4. anonymous

cook has 4 quarts that is 50% chicken stock. so at the moment it is 50% of 4 = 2 quarts chicken stock. so for example if she adds 3 quarts of chicken stock she will have 4+3= 7 quarts of liquid of which 2 + 3 = 5 quarts is chicken stock, and the percent will be 5/7 * 100. this is not what you want obviously, i am just trying to explain where the equation will come from. if she adds x quarts of chicken stock she will have 2+x quarts of chicken stock and 4+x quarts of liquid. you want $\frac{2+x}{4+x}=.75$ $2+x=.75(4+x)$ last equation says your two quarts of chicken stock plus your x quarts must be 75% of the total liquid. now we solve multiply out $x+2=.75x+.75\times 4= .75x+3$ $.25x=1$ subtract .75x from both sides and subtract 2 from both sides $x=\frac{1}{.25}=\frac{100}{25}=4$

5. safia21

and #3 thanks

6. anonymous

ok #3 looks like the previous one we did so let me be careful and not put the 1 on the wrong side like i did last time.

7. anonymous

keep seeming to put the 1 on the wrong side. you have two rates, r and r +1 $\frac{12}{r}=\frac{12}{r+1}+1$ slower person's time is one less more than faster persons. $\frac{12}{r}=\frac{12+r+1}{r+1}=\frac{r+13}{r+1}$ cross multiply$12(r+1)=r(r+13)$ $12r+12=r^2+13r$ $r^2+r-12=0$ $(r+4)(r-3)=0$ $r=3$ $r=-4$ so r = 3