Substitution is where we first Isolate one of the unknowns, express it in terms of the other unknown, and replace the isolated unknown with the other unknown in another equation. So that each time we only need to deal with one unknown. I think you'll get a better idea here:
First name these 2 equations with 1 and 2.
4x + 5y = 7 (1)
y = 3x + 9 (2)
Since y is already isolated in (2), so we can skip the isolation step and continue to substitute.
Substitute (2) into (1).
4x + 5(3x+9) = 7
Expand.
4x + 15x + 45 = 7
Group.
19x + 45 = 7
Shift +45 to the other side and turn it into -45.
19x = 7 - 45
19x = -38
Shift x19 to the other side, turn it into /19.
X = - 38/19
X = - 2
Now we solved x already, we can just substitute x= - 2 back to equation (2).
y = 3(-2) + 9
y = - 6 + 9
y = 3
So, the answers are
x = - 2
y = 3
It’s a. vertex is the lowest or highest point so (1,-8) x-intercepts is where the parabola hits the x axis so (-1,0) and (3,0)
six
Step-by-step explanation:
the reason is this: let steak be (s), pork be (p), grilled chicken be (gc), tea be (t), and coffee be (c)
now, we want to find the total number of outcomes, and this cannot be determined by a simple roll of the dice. you have to count the sample space required for EVERY outcome, and it has to lie within the conditions. so, assuming David only takes 1 main course and 1 drink, he would be down to six option, which are :
1. s & t
2. s & c
3. p & t
4. p & c
5. gc & t
6. gc & c
Move x
5y = - 15 - 3x
y = - 3 - 3/5x
y = - 3/5 - 3
-y = 3/5 + 3
