Asap! a pharmacist wishes to mix a solution that is 5% minoxidil. she has on hand 90 ml of a 1% solution and wishes to add some 7% solution to obtain the desired 5% solution. how much 7% solution should she add? whom ever answer correctly gets brainliest.

let x be volume of 1% and let y represent volume of 7% solution.

then the amount of minoxidil is

0.01x + 0.07y = 0.05(x+y)

but we have that x = 90 ml so

0.01(90) + 0.07y = 0.05(90+y)

0.9 + 0.07y = 4.5 + 0.05y

0.02y = 4.5-0.9

y = 3.6/ 0.02

y = 180 ml

she should add 180 ml of 7%

24

step-by-step explanation:

if it takes 8 pounds to make 12 divide 12 by 8 and you get 1.5, 1.5 x 16 = 24

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.