a chemist neds 90 milliliters of a 71% solution but has only 67% and 76% solutions available. Find how many milliliters of each that should be mixed to get the desired solution

a) 37 ml of 67%; 53 ml of 76%
b) 50ml of 67%; 40 ml of 76%
c) 40 ml of 67%; 50 ml of 76%
d) 53 ml of 67%; 37 ml of 76%

i need process please!

Question

a chemist neds 90 milliliters of a 71% solution but has only 67% and 76% solutions available. Find how many milliliters of each that should be mixed to get the desired solution

a) 37 ml of 67%; 53 ml of 76%
b) 50ml of 67%; 40 ml of 76%
c) 40 ml of 67%; 50 ml of 76%
d) 53 ml of 67%; 37 ml of 76%

i need process please!

anonymous · Answer

put $x$ as the number of ml of 76% solution so $90-x$ is the number of ml of 67% solution
you want the total to be 71% of 90  $.71\times 90=63.9$ so solve 
$$.76x+.67(90-x)=63.9$$ and solve for $x$

anonymous · Answer

i dont know how to please explain to mee!

anonymous · Answer

how to solve for $x$? probably easiest to multiply  both sides by 100 to get rid of annoying decimals and write 
$$.76x+.67(90-x)=63.9$$
$$76x+67(90-x)=6390$$ multiply out and get 
$$76x+6030-67x=6390$$ combine like terms and get 
$$9x+6030=6390$$ subtract 6030 from both sides and get 
$$9x=360$$ divide by 9 and get 
$$x=40$$

anonymous · Answer

now  don't forget that line number one i wrote was 
put $x $ as the number of ml of 76% so that means 
40 ml of the 76% solution and the other 
50 ml of the 67% solution

anonymous · Answer

thank you so muchhh <3

anonymous · Answer

yw

anonymous · Answer

please can you help me in an other :$