All categories

3 years ago

Solve each system using substitution. 3x+2y=23 1/2x-4=y

2 answers:

5 0

$\left\{\begin{array}{ccc}3x+2y=23&(1)\\y=\frac{1}{2}x-4&(2)\end{array}\right\\\\subtitute\ (2)\ to\ (1)\\\\3x+2(\frac{1}{2}x-4)=23\\3x+x-8=23\\4x-8=23\ \ \ \ |add\ 8\ to\ both\ sides\\4x=31\ \ \ \ \ |divide\ both\ sides\ by\ 4\\\boxed{x=7.75}\\\\subtitute\ the\ value\ of\ "x"\ to\ (2)\\\\y=\frac{1}{2}(7.75)-4\\y=3.875-4\\\boxed{y=-0.125}\\\\Answer:\boxed{ \left\[\begin{array}{ccc}x=7.75\ (7\frac{3}{4})\\\\y=-0.125\ (-\frac{1}{8})\end{array}\right}$

Harman [31]3 years ago

5 0

1: 3x+2y=23
2: 1/2x-4=y
We have that y=1/2x-4 in 2
So lets substitu y in 1
3x+2(1/2x-4)=23
3x+x-8=23
4x=23+8
4x=31
X = 7,75
Now lets replace x in 2:
1/2.7,75-4=y
3,875-4 + y
Y= - 0,125
So (x;y)=(7,75;-0.125)

You might be interested in

What is a difference of squares that has a factor of x 8? x2−4 x2−16 x2−64 x2−256

Aleksandr-060686 [28]

Answer:

Step-by-step explanation:

The factoring of the difference of squares is one of the special forms we use in the study of polynomials. It tells you ...

a² -b² = (a +b)(a -b)

You have a factor (x +8), so a=x, b=8, and the "expanded" form is ...

a² -b² = x² -8² = x² -64

5 0

2 years ago

Ashton walked into the restaurant and four employees were working registers usually trendline equation to predict how long he wi

MrRa [10]

Answer:

idk

Step-by-step explanation:

8 0

3 years ago

Write a number in each box to make an equation that has no real solution. Explain why this equation has no solution. 4(a-2) + a

borishaifa [10]

Answer:

4(a-2)+a=4a-2 No solution

Step-by-step explanation:

This would never be true. Try plugging in a as 1.

4(1-2)+1 isn't equal to 4(1)-2.

5 0

3 years ago

What are the roots for x^2+47=3 2x^2+50=4 2x^2+85=7

erastovalidia [21]

$x^2+47=3\ \ \ |-47\\x^2=-44\\if\ x\in\mathbb{R}\ then\ x\in\O\\if\ x\in\mathbb{C}\ then\ x=\sqrt{-44}=i\sqrt{44}=i\sqrt{4\cdot11}=\boxed{2\sqrt{11}i}\\---------------------------\\2x^2+50=4\ \ \ |-50\\2x^2=-46\ \ \ \ |:2\\x^2=-23\\if\ x\in\mathbb{R}\ then\ x\in\O\\if\ x\in\mathbb{C}\ then\ x=\sqrt{-23}=\boxed{\sqrt{23}i}\\---------------------------\\2x^2+85=7\ \ \ |-85\\2x^2=-78\ \ \ \ |:2\\x^2=-39\\if\ x\in\mathbb{R}\ then\ x\in\O\\if\ x\in\mathbb{C}\ then\ x=\sqrt{-39}=\boxed{\sqrt{39}i}$

7 0

3 years ago

Rsm question!How many liters of water must be added to 15 liters of 40 % sugar syrup to obtain 30 % sugar syrup?

Lyrx [107]

Answer:

$5\ liters$

Step-by-step explanation:

$Sugar\ in\ the\ syrup=40\%\\\\40\%\ of\ 15\ ltrs =\frac{40}{100}\times 15=6\ ltrs\\\\Now\ we\ have\ to\ obtain\ 30\%\ sugar\ syrup. Let\ total\ quantity\ of\ syrup=x\\\\30\%\ of\ x=6\\\\\frac{30}{100}\times x=6\\\\0.3\times x=6\\\\x=\frac{6}{0.3}\\\\x=20\ ltrs\\\\The\ amount\ of\ water\ to\ be\ added =20-15=5\ liters$

3 0

2 years ago