I suppose the / are absolute value lines.... so ill answer it that way, -(-2) simplifies to 2. -/-2/ simplifies to -2
Step-by-step explanation:
Sn=n/2(2a+(n-1)d). n=20
S20= 20/2 (2x5+(20-1)3 a=5
S20=10(10+57). d=8-5=3
S20=10x67
S20= 670
Hope this helps you
have a great day
Multiply the first equation by -1 and add it to the second one, getting
y-4z=-10
Multiply the first equation by 2 and add it to the third one, getting -2y+10z=26
As you can see, we eliminated x and turned it into two equations with 2 variables.
Multiply the first new equation by 2 and add it to the second one to get
2z=6 and z=3. Substitute it in to -2y+10z=26 to get y=2 and substitute it into <span>-x+y+z=4 to get x=1</span>
Let's say Miles Carlos drove = x and taook time = t1
Miles <span>Maria drove = y and took time = t2
But the total mile both drove = 233 and took time = 4.4 hrs
So , x + y = 233
t1 + t2 = 4.4
However, speed = distance / time
for Carlos, 55 = x / t1
for Maria, 50 = y / t2
</span><span>x + y = 233
</span><span>55 t1 + 50 t2 = 233
</span><span>t1 + t2 = 4.4
</span>50 t1 + 50 t2 = 220
5 t1 = 13
t1 = 2.6 hrs for Carlos
t2 = 1.8 hrs
Therefore Maria drove 4.4 hrs
