`a.`\(2x\left(x-5\right)-x\left(3+2x\right)=26\)
`=>2x^2-10x-3x-2x^2=26`
`=>-13x=26`
`=>x=-2`
`b.`\(6x\left(5x+3\right)+3x\left(1-10x\right)=7\)
`=>30x^2+18x+3x-30x=7`
`=>21x=7`
`=>x=1/3`
`a, 2x^2 - 10x - 3x - 2x^2 = 26`
`-> -13x = 26`
`-> x = -2`
`b, 30x^2 + 18x + 3x - 30x^2= 7`
`-> 21x = 7`
`-> x = 1/3`