Answer:
x=-1 and y=-5
Step-by-step explanation:
ሰላም!
Given expressions let them given as two equations
- y=2+7x....... equation (1)
- -2x+6y=-28..... equation (2)
Thus, substitute y=2+7x into equation (2)
simplify it
subtract 12 from both sides
divide both sides by 40
Therefore, as we get the value of x=-1 substitute it to equation (1) and solve for variable y
To be more sure make a cross check on both of the two expressions
Thus,
1) y=2+7x .... substitute y=-5 and x=-1 and check if it is equal
-5=2+7(-1)
-5=2-5
-5=-5
2)-2x+6y=-28... substitute and check
-2(-1)+6(-5)=-28
2-30=-28... (-a)(-b)=ab
-28=-28
Hope it helps!
Answer:
189
Step-by-step explanation:
You take 63% make it a decimal by dividing it by 100 and then you multiply it with 300. 300*.63=189.
c and a
by the way, thats easy. NO OFFENCE XD
Answer:
16
Step-by-step explanation:
x+y=30 solve for x x=30-y
substitute x with 30-y and solve
11.25x+22.4y=515.9
11.25(30-y)+22.4y=515.9
337.5+11.15y=515.9
11.15y=178.4
y=16
since we're solving for just large candles it's 16
if need small cangle number 30-16=14
Answer:
1.a=2
2. C x=2 and x=-3
Step-by-step explanation:
The standard form for the quadratic function is
ax^2 +bx+c
so we need to rewrite the function to be in this form
2x^2 -10 = 7x
Subtract 7x from each side
2x^2 -7x-10 = 7x-7x
2x^2 -7x-10 = 0
a =2, b= -7 c=-10
2. The quadratic formula is
-b ± sqrt(b^2 -4ac)
----------------------------
2a
2x^2 + 2x=12
Lest get the equation in proper form
2x^2 + 2x-12 = 12-12
2x^2 +2x-12 =0
a=2 b=2 c=-12
Lets substitute what we know
-2 ± sqrt(2^2 -4(2)(-12))
----------------------------
2(2)
-2 ± sqrt(4+96)
----------------------------
2(2)
-2 ± sqrt(100)
----------------------------
4
-2 ± 10
----------------------------
4
-2 + 10 -2-10
----------- and --------------
4 4
8/4 and -12/4
2 and -3
