Let's call Maria 'M' and Sal 'S'
Maria is 12 1/2 years older than Sal.
S + 12 1/2 = M
The sum of their ages is 28 1/2
S + M = 28 1/2
Solve for M in the second equation:
28 1/2 - S = M
The first equation is:
<span>S + 12 1/2 = M
</span>
Set them equal to each other since they both are equal to M.
28 1/2 - S = <span>S + 12 1/2
</span>
Basicaly, n = S, so your correct answer is B. 28 1/2 - n = n + 12 1/2
Subtract the 2x and divide by -4. y=1/2x-2 or y=x/2-2
10.) x+25=30
x=5
11.) 60=3x-12
72=3x
x=72/3
x=24
12.) <1+<2=90
<1+17=90
<1=90-17
m <1=73 degrees
13.) m <3+m <4=180
46+m <4=180
180-46=m<4
134=m<4
Ok so differentiate the function, then set it as an inequality, if the function is increasing the gradient is positive >0 (so just make the differentiated function more than 0 to solve for the set of values of x) :)
