Answer:
D
Step-by-step explanation:
2x + 3y = 18
3x - 3y = 12
the 3y and -3y cancel and you add the other like terms
5x = 30
x = 6
plug x back into any of the equations
2(6) + 3y = 18
12 + 3y = 18
3y = 6
y = 2
answer is (6,2)
ASSUMING This is a straight line so we gotta the formula for a straight line which is y=mx+b, where m represents the slope and b represents the y intercept.
First, we know this line passes through (5,8) and (9,2) we can use these for finding the equations. When we know two points, we use this formula:
y-y=m(x-x)
The first y is 8 and the second one is 2
The first x is 5 and the second one is 9
Plug it in:
8-2=m(5-9)
6=m(-4)
6/-4=m <— simplify this
m= -3/2
*NOTE: another way to find m is by calculating it (y-y)/(x-x)
Now we know m, we have to find b.
All you gotta do is plug everything you know back into the equation y=mx+b
y=mx+b
y=-3/2x+b <— now plug in a point we know(x,y)
8=-3/2(5)+b
8=-15/2+b
8-(-15/2)=b
b=8+15/2
b=16/2+15/2
b=31/2 (now you can write be as a fraction or a decimal in your equation, depending on what your teacher told you to use)
*NOTE: it is best to use fractions instead of decimals as it is more accurate sometimes.
Now we know all the variables that need to be known, we just need to rewrite the formula of the equation so the teacher can see.
m=-3/2
b=31/2
We don’t need to plug in x or y since it could have different values (since a straight line has MANY co-ordinates)
SO OUR EQUATION IS=
y=(-3/2)x+31/2
Hope you understand this, feel free to ask me anything!
1) Let x be the original speed that he was driving;
x mph ---> 1.5 hours
x+44 mph --> 2.5 hours
1.5x + 2.5(x+44)=206
1.5x+2.5x+110=206
4x=206-110
4x=96
x=24
Therefore, he was travelling at 24 mph in the fog.
2) Let x be the speed of 1 snail,
The other snail travels at the speed of x+1 cm/min
23x+23(x+1)=391 <-- solve for x
23x+23x+23=391
46x=368
x=368/46
x=8
Therefore one of the snail travels at 8 cm/min while the other goes at 9 cm/min
7) Let x be one crew
Then the other crew would be working at x+0.5
3.2x+3.2(x0.5)=8 <-- solve for x
3.2x+1.6x=8
4.8x=8
x=8/4.8
x=1.6666 or 1.7 miles
Therefore, one of the crew does 1.7 miles per day and the other crew does (0.5*1.7)=0.85 miles
Hope I helped :)
Answer:
18
Step-by-step explanation:
the factors and prime factorization of 36 and 54. The biggest common factor number is the GCF number. So the greatest common factor 36 and 54 is 18.
Answer:
Step-by-step explanation:
1). 10 = 
10(7 + x) = 1 + 7x
70 + 10x = 7x + 1
10x - 7x = 1 - 70
3x = -69
x = -23
2). 0.2 = 
0.2(12 + x) = 6 + 2x
2.4 + 0.2x = 6 + 2x
2.4 - 6 = 2x - 0.2x
1.8x = -3.6
x = -2
3). 0.8 = 
0.8(x + 0.5) = x
0.8x + 0.4 = x
x - 0.8x = 0.4
0.2x = 0.4
x = 2
4). 3.5 = 
3.5(0.5 - x) = 4 + 2x
1.75 - 3.5x = 4 + 2x
-3.5x - 2x = 4 - 1.75
-5.5x = 2.25
x = -
x = - 
