Find the range of values of x which satisfy the inequalities 4x - 7 ≤ 3x and 3x - 4 ≤ 4x
Answer Details
To solve the system of inequalities 4x - 7 ≤ y ≤ 3x and 3x - 4 ≤ y ≤ 4x, we can use the following steps:
1. For the first inequality, isolate y in the middle by adding 7 to both sides: 4x - 7 + 7 ≤ y + 7 ≤ 3x + 7, which simplifies to 4x ≤ y + 7 ≤ 3x + 7.
2. For the second inequality, isolate y in the middle by adding 4 to both sides: 3x - 4 + 4 ≤ y + 4 ≤ 4x + 4, which simplifies to 3x ≤ y + 4 ≤ 4x + 4.
3. We want to find the range of values of x that satisfy both inequalities. To do this, we need to find the intersection of the two intervals [4x, 3x + 7] and [3x, 4x + 4] for y.
4. We start by finding the maximum lower bound of the two intervals. The lower bound of [4x, 3x + 7] is 4x, and the lower bound of [3x, 4x + 4] is 4x. So the maximum lower bound is 4x.
5. We then find the minimum upper bound of the two intervals. The upper bound of [4x, 3x + 7] is 3x + 7, and the upper bound of [3x, 4x + 4] is 4x + 4. So the minimum upper bound is 3x + 7.
6. Therefore, the range of values of x that satisfy both inequalities is 4x ≤ y + 7 ≤ 3x + 7 and 3x - 4 ≤ y ≤ 4x, which simplifies to 4x ≤ y + 7 ≤ 3x + 7 and 3x - 4 ≤ y ≤ 4x.
7. To solve for x, we can use the second inequality: 3x - 4 ≤ y ≤ 4x. We can substitute the upper bound of y with 4x and the lower bound of y with 3x - 4 to get 3x - 4 ≤ 3x - 4 ≤ x ≤ 4x. Therefore, the range of values of x that satisfy both inequalities is -4 ≤ x ≤ 7.
Therefore, the correct option is "-4 ≤ x ≤ 7".