Year 9 CH 2G & 2H T2 Week 3

Answer explanation

To isolate x, subtract 5 from both sides: 3x = 17 - 5. Then, divide by 3: x = (17 - 5) / 3. Thus, the correct choice is x = \frac{17 - 5}{3}.

Answer explanation

Substituting x = 2 and y = -1 into 4x - y gives 4(2) - (-1) = 8 + 1 = 9. Thus, the correct answer is 4 \times 2 - (-1) = 8 + 1 = 9.

Answer explanation

To find the value of m^2 + 2n, substitute m = 3 and n = 5. Calculate: 3^2 = 9 and 2*5 = 10. Therefore, 9 + 10 = 19, which matches the correct answer choice.

Answer explanation

To isolate p, start with 7 = 2p + 9. Subtract 9 from both sides: 7 - 9 = 2p. This simplifies to -2 = 2p. Finally, divide by 2: p = (7 - 9)/2. Thus, the correct choice is p = \frac{7 - 9}{2}.

Answer explanation

Substituting a = -3 and b = 6 into the equation gives (-3)^2 - 6. Calculating this, we find 9 - 6 = 3, which matches the correct answer choice.

Answer explanation

To make s the subject, start with t - 4 = 3s. Add 4 to both sides: t = 3s + 4. Then, subtract 4 from both sides: t - 4 = 3s. Finally, divide by 3: s = (t - 4)/3. Thus, the correct answer is s = \frac{t - 4}{3}.

Answer explanation

To find the value of 3x + 4y, substitute x = 5 and y = 2. Calculate: 3 * 5 + 4 * 2 = 15 + 8 = 23. Thus, the correct answer is 23.

Solve for t: -13t > 26

• t > -2

• t > 2

• t < 2

• t < -2

Answer explanation

To solve -13t > 26, divide both sides by -13, which reverses the inequality: t < -2. Thus, the correct answer is t < -2.

Does the sign need to flip when solving?
-2x ≥ 22

• YES

• NO

Answer explanation

Yes, the sign needs to flip when dividing or multiplying both sides of an inequality by a negative number. Here, dividing by -2 changes the direction of the inequality, making it x ≤ -11.

Solve for k: -24 + k ≤ 10

• k ≤ 14

• 34 ≤ k

• k ≤ 34

• 14 ≤ k

Answer explanation

To solve for k, add 24 to both sides: k ≤ 10 + 24. This simplifies to k ≤ 34. Therefore, the correct answer is k ≤ 34.