Hi can anyone point me in the right direction with this:
5𝑥 +4𝑘𝑦 = 6
3𝑥 −20𝑘𝑦 = 26
are simultaneous equations where k is a constant.
a) Show that 𝑥 = 2
b) Given that 𝑦 = −2, determine the value of 𝑘
I don't know what to do with the constant or what it represents
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Simultaneous Equations with Constants? What to do watch
- Thread Starter
- 27-10-2017 10:59
- 27-10-2017 11:15
- 27-10-2017 11:28
a) multiply the 1st eq by 5. Add both eq to eliminate ky. solve to find x
b) Use either eq and substitute your x value (you worked out for part a). Substitue y=-2. Solve to find k.
- 27-10-2017 11:29
For future reference, just follow the order of the questions step by step- their just trying to confuse you. All your doing is applying your knowledge.
- 29-10-2017 16:48
"N/A IS THE NAME" gave good advice.
It is one of the basic steps for solving N Equations in N Unknowns.
In the present case, multiplying the first equation by 5 allows you to eliminate the ky term. The equations become
25 x + 20 ky = 30
3 x - 20 ky = 26
Now when these equations are added together, the result is
28 x = 56
Solving this equation for x is now simple.
Knowing x, and being given the value for y, either of the original equations can be used to plug these values in to solve for k.