Ask question

Ask question

All categories

3 years ago

15

Solve the system by the substitution method -4x + 3y = -7 y = 2x - 5

1 answer:

bagirrra123 [75]3 years ago

8 0

Answer: x=4 and y= 3

Step-by-step explanation: Solve for the first variable in one of the equations, then substitute the result into the other equation

You might be interested in

Determine all real numbers a$ such that the inequality $ |x^2 2ax 3a|\le2$ has exactly one solution in x$.

vovikov84 [41]

Answer:

$x=-1, S=\{x\:\in\mathbb{R}:x=-1\}$

Step-by-step explanation:

For the sake of clarity, assuming you meant:

$|x^{2}+2x+3|\le2$

1) Absolute Value or Modulus functions has one property that assures us that:

$If |a|$

2) Solving for x

$I) x^{2}+2x+3\geqslant -2\Rightarrow x^{2}+2x+5\geqslant 0 \Rightarrow x\geqslant \frac{-2\pm \sqrt{2^{2}-4*1*5}}{2} x'\geqslant \frac{-2+4i }{2} \:and\:x''\geqslant \frac{-2-4i }{2}$

Not defined in Real Set of Numbers

Evaluating $x^{2}+2x+3\leqslant 2$ :

$x^{2}+2x+3\leqslant 2\\x^{2}+2x+1\leqslant 0\\(x+1)(x+1)\leqslant 0 \Rightarrow S=\{-1\}$

3) So, since for the first case the Discriminant Δ <0, then the solutions presented for $x^{2}+2x+3\geqslant -2\: \in \mathbb{C}$ . The only solution in the Real Set for the inequality $|x^{2}+2x+3|\le2$ is $S=\{-1\}$ , i.e. x=-1.

8 0

3 years ago

What is the justification for step 4 in the solution process?

iogann1982 [59]

Answer:

Multiplication property of equality

Step-by-step explanation:

Given

Step 4: b = -27/8

Required

Which property justifies it?

First, it should be noted that step 4 is a result of step 3

When step 3 is multiplied by 3/8 on both sides, we have step 4;

i.e.

$\frac{8}{3b} = -9$

$\frac{8}{3b} * \frac{3}{8} = -9 * \frac{3}{8}$

$b = -9 * \frac{3}{8}$

$b = \frac{-9 * 3}{8}$

$b = \frac{-27}{8}$

<em>The property that allows 3/8 be multiplied on both sides is referred to as the multiplication property of equality</em>

3 0

3 years ago

A restaurant sells curried cashew soup. On Monday the cook uses 3/5 of a bag of cashew. On Tuesday the cook uses ½ as any cashew

Vadim26 [7]

Answer:

The restaurant cooked 3/10 as many cashews on Tuesday

Step-by-step explanation:

If the word problem says that they used 3/5 of a bag of cashews on Monday, and they used 1/2 AS MANY.

So "as many" gives us a clue to multiply.

3/5 * 1/2 = 3/10

So the restaurant cooks 3/10 bag of cashews on Tuesday

3 0

3 years ago

5*198 in distributive property

Mandarinka [93]

5 * 198 = 5(100 + 98) = (5 * 100) + (5 * 98) = 500 + 490 = 990

7 0

3 years ago

Please help <3 i don’t understand this question well i do but like idk how 2 word it

frutty [35]

Answer:

Square

Step-by-step explanation:

6 * $10^{8}$ = 600,000,000

I would put a decimal or dot to the right of 6 and count 8 zeros places to the right.

6. 0 0 0 0 0 0 0 0.

3 0

3 years ago