X-y=3=>x=3+y
X+2y=-6
=========
3+y+2y=-6
3+3y=-6
3y=-6-3
3y=-9
y=-3
X+2y=-6
X+2(-3)=-6
X-6=-6
X=0
a+2 a +1
= ------- / ------------------
a -5 (a - 3)(a - 5)
a+2 (a - 3)(a - 5)
= ------- * ------------------
a -5 a +1
(a+2)(a - 3)
= ----------------
a +1
a NOT equal 5 and -1
Answer:
150 mL
Step-by-step explanation:
We need a mixture that is at 50%, now we have 200 mL at 35% and another mixture that is at 70%, that is, we must calculate how much of this mixture is added, by the following equation
200 * 35% + x * 70% = 50% (x + 200)
70 + 0.7 * x = 0.5 * x + 100
0.7 * x - 0.5 * x = 100 - 70
0.2 * x = 30
x = 30 / 0.2
x = 150
150 mL must be added so that the mixture is 50%.
Lets say that the length of a rectangle is 12 cm and the width is 5 cm, you would add 12+12+5+5 (as in the length on both length sides and the width on both sides) so the perimeter of this rectangle is: 34 cm
