In 14 pounds of a 50% mixture we have 0.5*14=7pounds of cement
lets think that we need x pounds of mix of an 80% cement so in that mix we will have 0.8x pounds of cement. If we'll mix both we wiil have (14+x)pounds of mix and we have (0.8x+7) cement on it.
in mixture mix there are 60% of (x+14)pounds of cement so it is 0.6(x+14) of cement
make equation (sum of mix)
0.6(x+14)=0.8x+7
0.6x+8.4=0.8x+7
0.2x=1.4
x=7
Answer: engineer need 7pounds of 80% mix
P.s. look at the picture it more easy for understanding!
Answer:
-8 <_ x < -3
-7 <_ y < -2
Step-by-step explanation:
closed dot means it includes that number so in this case x is least than or equal to -8 and open dot means it doesn't include that value so x is less than -3 and does NOT include -3
and for the y value it's pretty self explanatory if u just count it (i might be off by a little cuz the photo quality is kinda fuzzy but i hope u get the gist!)
Answer:
5 1/4 cups
Step-by-step explanation:
Answer:

(You only need to give one solution)
Step-by-step explanation:
We have the following equation

First, we need to foil out the parenthesis

Now we can combine the like terms

Now, we need to factor this equation.
To factor this, we need to find a set of numbers that add together to get -3 and multiply to give us -4.
The pair of numbers that would do this would be 1 and -4.
This means that our factored form would be

As the first binomial is a difference of squares, it can be factored futher into

Now, we can get our solutions.
The first binomial will produce two complex (Not real) solutions.


So our solutions to this equation are
